Flashing headlights

wbduval

Member
I have a 2004 Envoy and the headlights are behaving erratically. They are on sometimes during daylight, and often are off at night. They flash off and on rapidly at times as well. I've replaced the relay several times, so that does not appear to be the issue. Any ideas and suggestions appreciated.
 

Blckshdw

Moderator
When this behavior is going on, do you see any change in the lights on your headlight switch? Could also be an issue with the BCM. When the auto lights are off when they should be on, can you turn the lights on manually from the switch, and vice versa?

I'm assuming when you say your lights are on during the day, you mean full power low beams, and not the DRLs
 

christo829

Well-Known Member
Someone on the old site had a similar problem that turned out to be the light sensor on the dash.
I can't recall if it was going bad or just came loose so it wasn't able to sense properly, but worth
checking.

Good Luck!

Chris
 
OP
OP
W

wbduval

Member
I hate to ask, but... are you sure you replaced the correct 'relay' (that isn't a relay) ?
Yes - have done it several times, so am sure it's the right one.

Someone on the old site had a similar problem that turned out to be the light sensor on the dash.
I can't recall if it was going bad or just came loose so it wasn't able to sense properly, but worth
checking.

Good Luck!

Chris
Thanks Chris - was thinking that might be the culprit, so will check that out.
 
OP
OP
W

wbduval

Member
When this behavior is going on, do you see any change in the lights on your headlight switch? Could also be an issue with the BCM. When the auto lights are off when they should be on, can you turn the lights on manually from the switch, and vice versa?

I'm assuming when you say your lights are on during the day, you mean full power low beams, and not the DRLs
The low beams will not turn on with the switch in these situations, but the high beams will work. I haven't double-checked, but I am pretty sure all 4 lights are on in that case.
And yes on the low beams (and not DRLs) - they are constantly on at times and will flicker rapidly at others.
 
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