Headlight Problem

[fredhouse]

Tonight pulling into my driveway i lost my headlights,i turned off truck and restarted and still didn't have them .I turned off again and went in to get a flash light took about 5 min.I again started the truck and lights are on now.wondering what i should check for.Thank you
2003 chevy trailblazer ext 5.3

 

[BlazingTrails]

Under the back seat on the driver side is the box that controls the lights. You could check for any loose connections? Do you have auto headlights? Did you manually turn the switch on and check that?

 

[fredhouse]

I did have them set to auto when they went out.I did turn them to each setting and they are all working now.

 

[Wooluf1952]

Relay #46 in the under hood fuse box controls the low beams. It can be flaky and work intermittently.

 

[triz]

Headlight relay in the front. If you need one I have one left just PM me. The relay has a tendency to heat up and lights only come on when it cools off again. You should be good for now but it will increase in how often it happens as time goes by.

 

[BlazingTrails]

I am thinking that maybe the sensor for the auto light is going out? If they work with switch it is going to be something in the auto control circuit.

 

[Wooluf1952]

The OP didn't mention using the switch until after the headlights worked again. But it is easy to check by swapping relay 45 and 46. If the lights work, the relay is suspect. However checking for loose wires is also a good idea,

 

[The_Roadie]

When they were dark, were both the high and low beams dead? If the lows were out and the highs worked, statistically it's the black relay in the front fuse block.

 

[fredhouse]

I don't know i didn't try the high-beams but both low beams were out.I just checked and they are all still working now but im going to replace the relay anyway

 

[C-ya]

This just happened to me last night after leaving my ham club meeting. I remembered the relay swap trick so I did that when I got home and the low beams worked. My high beams did work, but I couldn't drive "in town" with my high beams on, so I turned the fogs on for the 2 mile jaunt. It was only 9:30 p.m., so it was still a little light and no one flashed me. They came on automatically since it was dark enough. Going down the road (about 1/2 mile from my starting point), I noticed I didn't see any light on the signs from me so I hit the fogs after testing the highs.

This morning the lights came on as normal, and as normal I automatically turned them off and then thought about it and turned them back on to check them and they were on. I turned them back off and drove to work and then checked again. They worked, but I didn't leave them on long enough to get hot. I'll grab a relay after work and keep it in the truck and see if it happens again. Next offense gets the ban stick!

 

[RayGumm]

This relay fried on me recently. 40 friggin dollars. Stupid. Easy easy fix, tho, I guess that counts for something.