Faster than a bullet

I have a low beam when I choose it, but when I choose auto (low beam), the low beam doesn't work. I've replaced the relay twice. Each time it works for a short time on auto, but then stops and the only way I get the low beam is turning the switch to low beam on.

Any suggestions for explaining why the relay trips? I've removed the entire fuse box - opened it up, checked all the printed circuitry and all is working fine.

icntdrv55

Possibility that your ambient light sensor on the dash is faulty? That is what would send a signal to your headlights/relay to turn on when the switch is in 'auto' position.

myfunz

franman69

Faster than a bullet

After replacing the entire fuse box at about $800 or so, it turned out to be some other wire problem. Luckily, Chevrolet issued a recall on the problem shortly thereafter (having to do with the low beams now working) so I got the $800 back and the problem fixed.