Mechanics

CHEVY GREMLIN HIGH BEAMS

2005 Chevrolet Avalanche

Electrical problem
2005 Chevy Avalanche V8 Four Wheel Drive Automatic 39000 miles

About 2 months ago I had 35995 miles on my truck and took it in fore its last warrantee repair which included the collapsible part of the steering column, which they replaced. About 2 weeks later and no out of warranty, my battery was dead in the morning. The neighbor told me my headlights were on in the middle of the night. The same thing happened the following night. The third night my neighbor called at 11: 00 pm and told me they were on ugen. So I went out to investigate. The high beams were on but no taillights or any thing ells, just height beams. I tried everything to try to turn them off but nothing worked! Eventually the battery died. I charged the battery and it was fine. For about an hour when they came back on. At this point I unplugged the high beams and all was well. (Just no high beams). A month later now the weather is colder and my battery is dead every morning. I suspect the battery is no good now? Does that sound right? I return the truck to the dealership and they refuse responsibility. And they warned me that it will be”a hard one to diagnose” because it only happens at night when there not at work.
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Randoger
January 8, 2008.




All of the lighting in your truck goes through the BCM (body control module). Located next to steering column on left. Teh hi-low switch is on the column, but Im not sure if it has the ability to turn the hi-beams on without signal from the switch to do so.I take it this didnt happen before they took the column apart to repair it? Might have a wire that is grounding out intermittently in the column turning the lights on. As far as the battery goes. Have it load tested, that will tell you if it is any good.

Tiny
Jack42
Jan 9, 2008.
Is there a way fore me to test or trouble shoot the switch, BCM, or for a ground problem? Or do I have to start replacing them? Can the BCM be reprogrammed or would it need to be replaced?

Tiny
Randoger
Jan 9, 2008.
On the column wiring, the yellow/black wire is the " flash to pass" signal to the BCM and the Light Green/Black wire is hi-lo beam select. See if you can disconnect these wires and see if it comes on overnight. If not then the switch is most likely the problem, if it still does then the BCM is probably it.

Tiny
Jack42
Jan 9, 2008.
OK I had the battery tested and it was good. I bought a test light and put it on between the battery negative and the negative cable. It lit up I thought pretty bright. But I don’t now how bright it can go. I then unplugged every fuse 1 at a time. The light never changed at all.? My father in law has a 2004 Yukon. I thought I might put the tester on it to compare.
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Tiny
Randoger
Jan 10, 2008.
Mind you, when checking for a draw, the doors must be shut, or pin switches held down, key off, check for a hood light- has to be off.

Tiny
Jack42
Jan 10, 2008.
I have the exact same issue as Randoger. My high beams on my 2005 Avalanche come on when turning the ignition off. Day time or night. Sometimes they go off by themselves but will come on by themselves after several hours. No tail lights. No perimiter lights just the high beams. For now I have taken the fuses out that controls them. Any ideas for the cause or method to track it down. Was this issue ever resolved for Randoger.I know the issue is 2 years old but am hopeful that a solution was found.

Tiny
Gcrosby
Jan 10, 2011.

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