NEED HELP 2002 Envoy - No Face Vents plus No A/C ?

[tippy]

Hi -
My 2002 Envoy the A/C not working plus no air blowing from Face Vents !! [confused]

What I know so far -
* battery went dead.
* replaced with new battery.
..now no vents and A/C not working ---[confused]

* From Control Panel.
- Fan works OK.
- Fan speed works ok.
- Both Drivers and Passenger Temp Controls works OK - there is HEAT and can be adjusted for both Drivers and Passenger.
* Mode Switch;
- Floor Vent Air and Heat ok [no A/C]
- Top Vent Air [by windshield] and Heat = ok [but no A/C]
- Top Vent Air [by windshield] and Floor Vent = ok [but no A/C]
- Face Vent = No Air - No heat - No A/C. = Air Blows from Floor Vent (at some reduced air flow)

* Recirculation Switch = works ok
* A/C Button on controller seems to turn off via display [a/c off] /
* Controller OFF button works ok.

I really need my A/C to work not so much for me but for my poor doggy.

Any ideas on to get the A/C back up and running would greatly be appreciated.

Thanks

 

[TJBaker57]

Hi -
My 2002 Envoy the A/C not working plus no air blowing from Face Vents !! [confused]

What I know so far -
* battery went dead.
* replaced with new battery.
..now no vents and A/C not working ---[confused]

* From Control Panel.
- Fan works OK.
- Fan speed works ok.
- Both Drivers and Passenger Temp Controls works OK - there is HEAT and can be adjusted for both Drivers and Passenger.
* Mode Switch;
- Floor Vent Air and Heat ok [no A/C]
- Top Vent Air [by windshield] and Heat = ok [but no A/C]
- Top Vent Air [by windshield] and Floor Vent = ok [but no A/C]
- Face Vent = No Air - No heat - No A/C. = Air Blows from Floor Vent (at some reduced air flow)

* Recirculation Switch = works ok
* A/C Button on controller seems to turn off via display [a/c off] /
* Controller OFF button works ok.

I really need my A/C to work not so much for me but for my poor doggy.

Any ideas on to get the A/C back up and running would greatly be appreciated.

Thanks

When battery power is disconnected then reapplied to the HVAC control module this initiates a recalibration routine for all of the 5 air duct actuators.

The recalibration routine takes a minute or two during which the control module drives the actuators fully counterclockwise and clockwise until it senses they can go no further in each direction. This is how the controller knows the extents of each actuators limits of travel.

Unfortunately the 20 plus year old plastic gears in the actuators are now brittle and often break under the stress when they hit their limits during the time of the recalibration routine.

Often when this happens a clicking noise can be heard for a minute or so at key on.

It is also possible that when you replaced your battery the truck was started before the recalibration routine had enough time to complete. It is imperitive that the recalibration routine be allowed to complete before any action is taken with HVAC controls.

You could try running the recalibration routine again by removing the HVAC B fuse under rear seat for a minute or so then replace it. Turn the key ON but DO NO TOUCH any HVAC controls for a couple of minutes.

 

[tippy]

When battery power is disconnected then reapplied to the HVAC control module this initiates a recalibration routine for all of the 5 air duct actuators.

The recalibration routine takes a minute or two during which the control module drives the actuators fully counterclockwise and clockwise until it senses they can go no further in each direction. This is how the controller knows the extents of each actuators limits of travel.

Unfortunately the 20 plus year old plastic gears in the actuators are now brittle and often break under the stress when they hit their limits during the time of the recalibration routine.

Often when this happens a clicking noise can be heard for a minute or so at key on.

It is also possible that when you replaced your battery the truck was started before the recalibration routine had enough time to complete. It is imperitive that the recalibration routine be allowed to complete before any action is taken with HVAC controls.

You could try running the recalibration routine again by removing the HVAC B fuse under rear seat for a minute or so then replace it. Turn the key ON.....

Thanks for your quick response

What you mentioned does make sense as its a 20 + year old vehicle - things can get brittle - and perhaps I played with the controls before letting it finish calibrating --

I just spend all day - 6 plus hours - trying different things -
here it is;
Removed all the hvac fuses - both behind drivers seat and under the hood - waited 3 minutes and put the fuses back in - tried many different ways to get it to calibrate (ignition and heater control panel settings) Ect - no luck ;
then I disconnected the batteries terminals and removed all the the hvac fuses plus swapped the A/C relay under the hood - waited 2 hours tried again - connected battery and all fusses back in place - still no luck -

Here some things that confuses me;
Point 1 - * I can hear the system trying to calibrate but no "clicking noise" as mentioned.
Point 2 * Along with the face vents not working the A/C will not turn on (even with different A/C relay) - (btw I did meter all the fuses and all good).
So, now I'm wondering besides having no air flow on face vents why is the A/C is not being turned on - ?
what does the no air on face vent have to do with the A/C not working?
Is the face vent issue related to the A/C not working? - if it is a faulty actuators and if replaced will this get the A/C to work as well?
Does anyone here on this forum know - ..?

[Also, I forgot to mention that when Heating/ AC is in AUTO mode some little air comes out the floor vents but no air from Face vents or the Front upper windshield vents - not sure if this helps with the issue on hand ..]

Any thoughts?

{if I do not get this fix soon its either get rid of the vehicle or the cute little doggy )

 

[TJBaker57]

Point 1 - * I can hear the system trying to calibrate but no "clicking noise" as mentioned.

Clicking is not the only failure mode. Sometimes the gear(s) crack and are then loose on the shaft they attach to so the shaft then spins without moving the gear. This doesn't make a clicking sound but still causes failure of the actuator.

Point 2 * Along with the face vents not working the A/C will not turn on

Does this statement mean the air does not get cold and the compressor is not seen to engage?

The blower is still working OK? (you can hear it running and maybe air does come out 'somewhere'?)

what does the no air on face vent have to do with the A/C not working?
Is the face vent issue related to the A/C not working? - if it is a faulty actuators and if replaced will this get the A/C to work as well?

The actuators only control where the air goes, they do not have any direct effect on A/C heating or cooling operations.


The operation of the A/C cooling system is computer controlled. There are like a half dozen prerequisites that must be met before the engine control computer will activate the A/C relay to turn on the compressor.

At your HVAC control,,, is there an outside temperature displayed? Does it seem correct?

 

[tippy]

Clicking is not the only failure mode. Sometimes the gear(s) crack and are then loose on the shaft they attach to so the shaft then spins without moving the gear. This doesn't make a clicking sound but still causes failure of the actuator.




Does this statement mean the air does not get cold and the compressor is not seen to engage?

The blower is still working OK? (you can hear it running and maybe air does come out 'somewhere'?)





The actuators only control where the air goes, they do not have any direct effect on A/C heating or cooling operations.


The operation of the A/C cooling system is computer controlled. There are like a half dozen prerequisites that must be met before the engine control computer will activate the A/C relay to turn on the compressor.

At your HVAC control,,, is there an outside temperature displayed? Does it seem correct?

Thank you for chiming in to hopefully solve this nightmare !

"Does this statement mean the air does not get cold and the compressor is not seen to engage?"

CORRECT - No standard A/C cold and the compressor is not seen to engage.
-----
"The blower is still working OK? (you can hear it running and maybe air does come out 'somewhere'?)"

YES - the blower is working fine. (fan speed able to adjust)
but no air coming from the Face Vents - air coming only thru Floor Vents and Top Vent [by windshield]. but no A/C cold -
-----
"At your HVAC control,,, is there an outside temperature displayed? Does it seem correct?"

YES - it has ext temp display and its correct - compared it to a portable thermostat and only .5 C difference.
-----
"The actuators only control where the air goes, they do not have any direct effect on A/C heating or cooling operations."

Perhaps then it sounds more than just the actuator causing this problem- or if there is no air blowing thru the face vents the engine control computer will not engage the A/C ? or something else all together?

Any other ideas please?

Thanks

 

[Mathoran]

I know on my manual HVAC if its set to defrost (windshield vent) it wont let the a/c work. Ive never used the electronic controls but could it somehow have changed modes into defrost? From what I read it should be on Vent mode. Sometimes its the simple things.

 

[TJBaker57]

no air coming from the Face Vents - air coming only thru Floor Vents and Top Vent [by windshield]. but no A/C cold -

I would begin by replacing the Mode and Defrost actuators. These are right next to each other in the drivers side footwell above the area of the accelerator pedal. Other than there being a plastic duct needing to be removed after removing some lower panels these two are the easiest actuators to replace. They control where the air goes.

This is from my 2002 TrailBlazer so the part numbers should be the same as yours. They will have been superceded but even so they are NOT THE SAME as other years.




I asked about the outside temp display because that is one of the prerequisites for the compressor operation. Must be higher than I think it is 40°F or the compressor will not turn on.

if there is no air blowing thru the face vents the engine control computer will not engage the A/C ?

The engine control computer knows nothing of where the actuators are or where the air is blowing.

Since the compressor affects the engine operations it is the engine control computer that controls compressor operation.

The Engine Computer receives a request from the HVAC computer to engage the compressor as determined by the HVAC controller.

Have a read through this to get an idea of how things work here...

Heating and A/C Operation — 2002 GMC Envoy 4WD L6-4.2L VIN S Service Manual | Operation CHARM

Detailed repair manual for the 2002 GMC Envoy 4WD L6-4.2L VIN S.

charm.li

 

[Mooseman]

I know on my manual HVAC if its set to defrost (windshield vent) it wont let the a/c work. Ive never used the electronic controls but could it somehow have changed modes into defrost? From what I read it should be on Vent mode. Sometimes its the simple things.

That is not normal. A/C should always come on with any defrost position, even split defrost/floor position. In fact, you can't even turn the A/C off in defrost. Only time it won't turn on is when outside temps are below freezing. I have a manual HVAC and that's how it works. If I want to prevent it, I have to disconnect something like the low side switch or the relay.

 

[tippy]

I would begin by replacing the Mode and Defrost actuators. These are right next to each other in the drivers side footwell above the area of the accelerator pedal. Other than there being a plastic duct needing to be removed after removing some lower panels these two are the easiest actuators to replace. They control where the air goes.

This is from my 2002 TrailBlazer so the part numbers should be the same as yours. They will have been superceded but even so they are NOT THE SAME as other years.

View attachment 117758


I asked about the outside temp display because that is one of the prerequisites for the compressor operation. Must be higher than I think it is 40°F or the compressor will not turn on.







The engine control computer knows nothing of where the actuators are or where the air is blowing.

Since the compressor affects the engine operations it is the engine control computer that controls compressor operation.

The Engine Computer receives a request from the HVAC computer to engage the compressor as determined by the HVAC controller.

Have a read through this to get an idea of how things work here...

Heating and A/C Operation — 2002 GMC Envoy 4WD L6-4.2L VIN S Service Manual | Operation CHARM

Detailed repair manual for the 2002 GMC Envoy 4WD L6-4.2L VIN S.

charm.li

Thanks TJ - for such valuable information and with a cool manual as well - that's totally awesome !!!
Alright I will replace the actuators as recommended - this makes sense as after all it looks like they control the air flow thru the Face Vents - although will this enable the A/C works again - sounds we are not sure at this point in time - I pray its not the In-Dash Hvac Control Panel as they can be a bit pricey - going to do it myself as I don't like mechanics - - once replaced I will follow up and post the results - Thank you for your help !-

 

[tippy]

That is not normal. A/C should always come on with any defrost position, even split defrost/floor position. In fact, you can't even turn the A/C off in defrost. Only time it won't turn on is when outside temps are below freezing. I have a manual HVAC and that's how it works. If I want to prevent it, I have to disconnect something like the low side switch or the relay.

Thanks Mooseman - for clearing that up - I wasn't sure how that worked but now I know - - as you know there is no air from Face Vents and same time no A/C anywhere - so leads me to believe that perhaps I'm facing 2 separate issues here - once I replace the actuators as per TJ's suggestion then will the A/C get back up and running ? - maybe, maybe not - maybe its the Hvac Control Panel causing all the issues - what do you think?

 

[Mooseman]

The failing actuators are just a coincidence. To know what is preventing the A/C clutch from engaging, you would need to do some diagnostics. A quick test you could do is turn on the A/C and jumper the low side pressure switch. If the clutch comes on, it's either low on refrigerant or the low switch is defective. You would need some A/C pressure gauges to determine which. If it still doesn't come on after jumping the switch, some other quick tests is at the A/C clutch relay. Check that power is present on two of the connectors and if the the PCM is sending a ground signal to activate the relay. If it is and the power is all good, try jumping the relay to turn on the clutch. If it still doesn't come on and there is power getting to the clutch, then the clutch is toast. If the clutch does turn on, then the relay is probably toast. Swap it with another same one (I think the horn is the same).

If the PCM is not sending a ground signal to the relay, then it is not happy about something else or the HVAC control panel is not sending the signal to the PCM, which could mean it's defective. At this point you may need a scanner capable of reading multiple data related to the PCM and HVAC to see what they are sending and receiving from each other.

Instead of getting a new one, you can get a used one from a same year truck and wheelbase (EXT/SWB) and swap it without needing to have it programmed. Much cheaper especially if you get one from a Pick-n-Pull.

 

[tippy]

Mooseman - thank you for your detail response - there is one thing I'm beginning to understand is that YOU really really really know your stuff !! NICE Yes it looks like I have 2 separate issues and lucky me both at same time
As per your suggestions this is what I have done so far - I did jumper the low side pressure circuit and the clutch did come on - so far looking good, right - while jumper in place I quickly checked the air flow and it was still warm (same temp prior to jumping) - now, would one be correct to say that in this state while the compressor is running and if there was refrigerant in the system the air at the vents should start to feel cooler?
Since the air at vents are still warm perhaps its an indication that the system needs refrigerant - although we still don't know about the low pressure AC switch - is this the way to look at it or this is not how the AC system works?

Thanks

 

[Mooseman]

That is correct. Looks like the system is low or empty of refrigerant. I wouldn't run it too much like this as you may be just be pumping air around in the system and could damage the compressor.

Now even before looking at the refrigerant issue, you can first address the vent mode actuator issue and then the refrigerant. I would not recommend using DIY cans as you may have air in the system and possibly a large leak. This will require diagnostics to find that leak.

 

[tippy]

That is correct. Looks like the system is low or empty of refrigerant. I wouldn't run it too much like this as you may be just be pumping air around in the system and could damage the compressor.

Now even before looking at the refrigerant issue, you can first address the vent mode actuator issue and then the refrigerant. I would not recommend using DIY cans as you may have air in the system and possibly a large leak. This will require diagnostics to find that leak.

Ok will do - planning to do the actuators this weekend (as long as there is no rain ) - will keep you posted on how many times I have yelled and screamed while doing this - Thanks again for your help thus far !!

 

[tippy]

--

 

[tippy]

That is correct. Looks like the system is low or empty of refrigerant. I wouldn't run it too much like this as you may be just be pumping air around in the system and could damage the compressor.

Now even before looking at the refrigerant issue, you can first address the vent mode actuator issue and then the refrigerant. I would not recommend using DIY cans as you may have air in the system and possibly a large leak. This will require diagnostics to find that leak.

Alright here is update;

Actuators = Started to replaced the actuators and just more than 3 hours into it found out that I didn't have the proper sockets - went to Lordco and they didn't have any in stock - still searching - yes no room to move - really really tight spot - not happy

A/C system = purchased manifold gauge set and decided to hook them up - here are the readings with car not running;
Low Pressure = jumped to 5 psi
High Pressure = needle slightly moved to almost 1 psi

A/C system: just wondering what you suggest for the next best step ?

 

[TJBaker57]

Low Pressure = jumped to 5 psi
High Pressure = needle slightly moved to almost 1 psi

This means your system is essentially empty. Devoid of refrigereant. Most likely there is a leak somewhere. Under NO CIRCUMSTANCES should the compressor be made to run in this condition.

The leak must be found and the system fully evacuated after the leak is found and repaired.

 

[tippy]

This means your system is essentially empty. Devoid of refrigereant. Most likely there is a leak somewhere. Under NO CIRCUMSTANCES should the compressor be made to run in this condition.

The leak must be found and the system fully evacuated after the leak is found and repaired.

Thanks TJ for your input - alright, I will NOT run the compressor at this stage -
Now comes the fun part -
In this state;
* how does one go about confirming that the compressor is actually working as it should ?
* What is the best method now (step by step) to search in determining whether or not there is a leak ?

Here are the tools I have on hand;
- manifold gauge
- vacuum pump
- air compressor
Beside a bottle of whisky and Tylenol Is there anything else I need to get this done ?

I'm familiar with refilling after no leaks - does the system need the PAG oil added upon refilling with the new refrigerant?
---
About the MODE actuator unit - received it in which the slot are lined up in the 1 o'clock position - is this the correct position upon install in which thereafter hvac system will successfully complete recalibration process?

Thanks and looking forward to your input

 

[Mooseman]

* how does one go about confirming that the compressor is actually working as it should ?

If it was coming on and it didn't do any weird noises, it should be fine. It can't be confirmed it actually can pump properly until the system is evacuated, refilled and run.

* What is the best method now (step by step) to search in determining whether or not there is a leak ?

There are a couple of methods. First one would be to use a UV light and try to find the leak if it had UV dye in the system (most do). If that doesn't work or nothing is visible, my preferred method is to use a leak detector. You would put one can of refrigerant and then check everywhere on the system. This video is pretty good to explain how to use it.

I would add that if the system does seem to retain the refrigerant long enough to check, then it could be a small leak that just lost all the refrigerant over time. I would also remove the caps and check the Schrader valves. I would also insert the probe into the condensate drain tube as any leaking gas would drop down into it.

There are also other methods if you have a large leak like connecting it to shop air and listening for leaking air or using soapy water to look for bubbles. However if it's the evaporator in the dash, the leak detector is the only way to confirm it. I had that and it's not a fun job to replace.

What's your history with this truck? Are you a new-to-you owner and trying to fix it or has had it for a while and have seen this system work before? Did it sit a long time? It could just be a small leak that leaked out over time.

As for the socket, it's not metric. IIRC, it's something like a 3/32".

 

[TJBaker57]

preferred method is to use a leak detector. You would put one can of refrigerant and then check everywhere on the system.

I would say to attempt to evacuate the system before adding the refrigerant for the leak checking with detector. This will get air out of the system and possibly moisture as well.

Vacuum is also a good leak test. See if you can pull the pressure down to 29 inches of vacuum then close the manifold valves and see if it holds that vacuum for ten minutes or so.

If the vacuum decays then there is a leak.

Is 29 inches of vacuum enough to properly evacuate a system before recharging in preparation for putting the system into use? No way, Not even close. But it will prove the presence of leak(s).

 

[tippy]

If it was coming on and it didn't do any weird noises, it should be fine. It can't be confirmed it actually can pump properly until the system is evacuated, refilled and run.


There are a couple of methods. First one would be to use a UV light and try to find the leak if it had UV dye in the system (most do). If that doesn't work or nothing is visible, my preferred method is to use a leak detector. You would put one can of refrigerant and then check everywhere on the system. This video is pretty good to explain how to use it.

I would add that if the system does seem to retain the refrigerant long enough to check, then it could be a small leak that just lost all the refrigerant over time. I would also remove the caps and check the Schrader valves. I would also insert the probe into the condensate drain tube as any leaking gas would drop down into it.

There are also other methods if you have a large leak like connecting it to shop air and listening for leaking air or using soapy water to look for bubbles. However if it's the evaporator in the dash, the leak detector is the only way to confirm it. I had that and it's not a fun job to replace.

What's your history with this truck? Are you a new-to-you owner and trying to fix it or has had it for a while and have seen this system work before? Did it sit a long time? It could just be a small leak that leaked out over time.

As for the socket, it's not metric. IIRC, it's something like a 3/32".

Mooseman, thanks for your suggestions

* when I bypassed the low pressure switch to make the compressor run (momentarily) it DIDN"T make any noise at all - I didn't even hear it start up - so that is good news

* thanks for the cool video - have now ordered a leak detector - and its on its way )

* The history of my vehicle - from what I understand the 1 st owner was a lady - then about 10 year ago it was sold to a teenager - he tried his best to maintain it but due to the lack of funds a lot of things were neglected -

So now I came along - i noticed it wasn't maintained very well - the outside body / paint was in very good shape - the interior was in excellent shape - engine and trany were sound - (he told me that it didn't burn oil - well over time I found out he was right and to this day it doesn't burn a drop of oil -

So made him an offer and now I have been the owner for the last 10 years or so - since the teenager didn't repair things like they should , I had to do it -

A lot of things needed repairing - brakes - axles - shocks - spark plugs - rear end - wheel bearings - rotors - and much more - did I take it to a mechanic !!! - NOPE, I spend 3 months day and night -(mostly nights) to get it the way it needed to be and get it road worthy - the only time it came close to a mechanic shop was when i had new tires installed - had the trany rebuild - and had the cracked windshield replaced -
It been 10 + years and it been purring like a kitten - besides regular maintenance I haven't put a cent into it since -

You asked me if everything worked before - yes HVAC system was working very well -
BUT (ya I know there is always a BUT -
THE CAR HAS BEEN SITTING STILL FOR SEVERAL MONTHS NOW - I have been away and couldn't find anyone to look after it -
So, therefore I have a pretty good feeling of why the issues are popping up like they have been with the HVAC system - I hope it only a very tiny small leak cause its been sitting - and it will resolve once it operates again - you think that too?
(I will make another post on what I discovered upon the removal of the MODE actuator) -

Ok that is the history of the car - and even though I have spend like mega hours on just trying to reach the actuators - that's ok its only my time and a little $$ - far better than taking it to a mechanic - right -?

Please note - I enjoy working on the car but I'm absolutely clueless about the HVAC system and mainly no AC knowledge -that's why I'm reaching out - (but at least now I'm able to interpret the difference between the LOW and HIGH manifold gauges - )

Thanks to you Mooseman & TJ too for your help thus far !- much appreciate !!

 

[tippy]

I would begin by replacing the Mode and Defrost actuators. These are right next to each other in the drivers side footwell above the area of the accelerator pedal. Other than there being a plastic duct needing to be removed after removing some lower panels these two are the easiest actuators to replace. They control where the air goes.

This is from my 2002 TrailBlazer so the part numbers should be the same as yours. They will have been superceded but even so they are NOT THE SAME as other years.

View attachment 117758


I asked about the outside temp display because that is one of the prerequisites for the compressor operation. Must be higher than I think it is 40°F or the compressor will not turn on.







The engine control computer knows nothing of where the actuators are or where the air is blowing.

Since the compressor affects the engine operations it is the engine control computer that controls compressor operation.

The Engine Computer receives a request from the HVAC computer to engage the compressor as determined by the HVAC controller.

Have a read through this to get an idea of how things work here...

Heating and A/C Operation — 2002 GMC Envoy 4WD L6-4.2L VIN S Service Manual | Operation CHARM

Detailed repair manual for the 2002 GMC Envoy 4WD L6-4.2L VIN S.

charm.li

Alright after tearing the car apart I was able to get to both the DEFROST and MODE actuator - TJ they are the same model as what you have - after some testing the DEFROST actuator seems to be working ok - just in case someone is wondering the way my actuators work - when cam at the 11 o'clock position = off (aka; vent fully closed) @ 12 o'clock position vent partially open/closed -@ 1 o'clock position on (aka; vent fully open) -

Then looking at the MODE actuator while mounted it was in the (11 o'clock) position (closed) - so no air from the face vents - so far so good - at control panel selected face vent - the cam on the MODE actuator did not move no matter which settings selected at control panel - at control panel I left the setting on Face Vents and I banged (tapped softly) on the actuator - to my pleasant surprise the actuator started to work again - but my joy was short lived as when it got back to the closed position it wouldn't work - tried tapping but stuck in closed position - not moving -

I started the removal process - lucky the 2 mounting screws were loose and easily to remove - pulled on the actuator and with not too much force it came out - BUT, ya the crazy BUT word again - - it didn't come out complete -some of the items inside the CAM wanted to stay behind which are still on the vent door post -
** I have attached screen shot of both the CURRENT and NEW actuators so you can see what I'm taking about - **

Then when I started to open / close the face vent door underneath manually I noticed that when the vent doors are in closed position and then upon trying to move them to open position it seems like there is a lot of resistance to get them started - (like the doors are stuck) - once i get them to travel the resistance wasn't as bad - its more so getting them to move from the closed position - I do now suspect that while to car was sitting still for some time without any movement over time perhaps the vent door mechanism siezed up - and that is what perhaps its putting stress the actuator.

Now for some questions;
1 - should the face vent doors move (travel) freely from open to close or close to open position smoothly without out any stickiness when stating out?

2 - Looking at the old / new MODE actuator - did I order the wrong one? - or?

Pictures
Top and 2nd from top = New
3rd and 4th from top = Old


Thanks

 

[Mooseman]

I have found that the initial move from closed position is a little resistant but would be free after, so basically like yours. I think it's a combination of gravity and the foam seal on the door edge that prevents it from initially moving freely.

That old actuator was definitely broken. The new one seems to be the correct one. As long as it's the correct one for your year (2002 was a one year part), it should be fine.

 

[Mooseman]

Also be careful when trying to pull that piece off the shaft if it's really stuck on there. That shaft can break.

 

[TJBaker57]

be careful when trying to pull that piece off the shaft if it's really stuck on there. That shaft can break.

it didn't come out complete -some of the items inside the CAM wanted to stay behind which are still on the vent door post -

As Mooseman said, be careful when getting that metallic part off the door shaft. They can get quite stuck on there and you most definitely do NOT want to break the door shaft.

You might want to try some sort of penetrating lubricant to loosen it up?

I actually fashioned myself a puller to remove one of my actuators. My puller pushes on the shaft while pulling on the metal part of the actuator.





It looks like your actuator final drive gear cracked, and that released the tension holding it to that metal piece that is now stuck on the door shaft.

 

[tippy]

I would say to attempt to evacuate the system before adding the refrigerant for the leak checking with detector. This will get air out of the system and possibly moisture as well.

Vacuum is also a good leak test. See if you can pull the pressure down to 29 inches of vacuum then close the manifold valves and see if it holds that vacuum for ten minutes or so.

If the vacuum decays then there is a leak.

Is 29 inches of vacuum enough to properly evacuate a system before recharging in preparation for putting the system into use? No way, Not even close. But it will prove the presence of leak(s).

Thanks TJ -
As per your suggestion I plan to do some vacuuming tomorrow - last time I mentioned the word "vacuuming" out loud the better half jumped up for joy

When you said;
" Is 29 inches of vacuum enough to properly evacuate a system before recharging in preparation for putting the system into use? No way, Not even close. But it will prove the presence of leak(s).
Just wondering "No way, Not even close" - what does that mean or signify?

Thank you

 

[tippy]

As Mooseman said, be careful when getting that metallic part off the door shaft. They can get quite stuck on there and you most definitely do NOT want to break the door shaft.

You might want to try some sort of penetrating lubricant to loosen it up?

I actually fashioned myself a puller to remove one of my actuators. My puller pushes on the shaft while pulling on the metal part of the actuator.

View attachment 117773View attachment 117774



It looks like your actuator final drive gear cracked, and that released the tension holding it to that metal piece that is now stuck on the door shaft.

View attachment 117775

Its very hard to see but TJ you have a very good eye in spotting that hair line crack as that is exactly the way it is ..

After many - many hours of fighting - yelling and screaming with that crazy actuator - it finally came off like butter - upcoming will share how I was able to do it

Thank you !

 

[TJBaker57]

When you said;
" Is 29 inches of vacuum enough to properly evacuate a system before recharging in preparation for putting the system into use? No way, Not even close. But it will prove the presence of leak(s).
Just wondering "No way, Not even close" - what does that mean or signify

It means that vacuuming an AC system to 29.00 inches of mercury is really not good enough to properly prepare an ac system for recharging. It will not remove the moisture in the system.

An AC system should be evacuated ideally to no less than 29.90 inches of mercury. That's about 500 microns on a proper electronic vacuum gauge. It may be difficult to achieve this level of vacuum.

It took me like 16 hours to get this......





Unfortunately a standard manifold gauge set cannot even show that value. So in reality I would imagine the DIY folks never really know what vacuum they are getting.







Best you can do is get as low as it will go then valve it off for like 10 minutes or more and see that the reading does not rise.

 

[tippy]

As Mooseman said, be careful when getting that metallic part off the door shaft. They can get quite stuck on there and you most definitely do NOT want to break the door shaft.

You might want to try some sort of penetrating lubricant to loosen it up?

I actually fashioned myself a puller to remove one of my actuators. My puller pushes on the shaft while pulling on the metal part of the actuator.

View attachment 117773View attachment 117774



It looks like your actuator final drive gear cracked, and that released the tension holding it to that metal piece that is now stuck on the door shaft.

View attachment 117775

Ok I was finally able to remove the MODE actuator ONLY by using the Cool Tool as well - Great Minds Think Alike !
(took a while to build but wouldn't work without it)



Here it is in Action LIVE on how it works !
Watch It Here....

 

[tippy]

It means that vacuuming an AC system to 29.00 inches of mercury is really not good enough to properly prepare an ac system for recharging. It will not remove the moisture in the system.

An AC system should be evacuated ideally to no less than 29.90 inches of mercury. That's about 500 microns on a proper electronic vacuum gauge. It may be difficult to achieve this level of vacuum.

It took me like 16 hours to get this......

View attachment 117787



Unfortunately a standard manifold gauge set cannot even show that value. So in reality I would imagine the DIY folks never really know what vacuum they are getting.




View attachment 117788


Best you can do is get as low as it will go then valve it off for like 10 minutes or more and see that the reading does not rise.

Hi

Ok today I hooked up vacuum ;

Vacuum pressure Low side = between -29 psi to -30psi
(but closer to -30 psi)
Vacuum pressure High side = needle bottom out

After 45 min;
Low side = - 28 psi
High side = needle bottom out

After 90 min;
Low side = -27
High side = needle bottom out

After 150 min;
Low side = -26
High side = needle bottom out

Now thinking about it perhaps I let too much time pass before looking at the gauges under vacuum

What you think is next best move?

Thanks

 

[Mooseman]

I've never seen a system to hold that high a vacuum and not lose 1-2hg after an hour. I'd fill that system with the appropriate amount and be happy.

 

[tippy]

I've never seen a system to hold that high a vacuum and not lose 1-2hg after an hour. I'd fill that system with the appropriate amount and be happy.

Wow that is very good news as I thought with such a drop I would perhaps be dealing with a big, big leak somewhere - ok will proceed to perform 100% vacuum and then fill it up - then lets see what happens - thank you for your help !

 

[tippy]

Hi

Getting ready to add refrigerant but just double checking for the correct amount - (Standard A/C= 1.8 and with Rear A/C = 3)
There is a console between the drivers and passenger seat - (see pic) does this mean this envoy its equipped with Rear A/C system?

Thanks

 

[Mooseman]

SWB (standard): 1.8
LWB (EXT/XL with real rear A/C): 3

You have a SWB. I know because the LWB doesn't have those vents in the center console but does have the controls. Those vents just pull air from the front HVAC through a duct in the console.

 

[tippy]

Update;

I was able to vacuum and recharge the A/C system;
* BTW - Let Vacuum pressure sit for 5 days straight and did not drop below -26 Psi.

Here are the results -

Ambient Temp = 71 F

With Compressor Running;
Low Pressure Reading = approx. 41 Psi
Hi Pressure Reading = approx. 152 Psi

Temperature at Face Vent = 11.4 C (52.5 F)
(yes face vent is working now )

Thank you

 

[Mooseman]

Good job!