Headlight Problems

Bukmaster · March 20, 2008

The headlights on my 99 Silverado have quit working. Every other light is working including the fog lights. I have swapped the relay, fuses, switch, and headlights from my 01 2500hd to no avail. I notice that the switch works for the running lights, dome overide and dimmer but the actual switch lights do not work. The funny thing is that I have power to both wires on all four headlight plugs instead of one hot and one ground. I have had the four high conversion on this truck for years but i have just unhooked it thinking that might have been the problem. I am thinking that i have a BCM problem but thought I would run it by you guys to see what your opinions are. Am I missing anything simple or obvious? I hope so!

Thanks , Bill

Trav_13 · March 20, 2008

The headlights on my 99 Silverado have quit working. Every other light is working including the fog lights. I have swapped the relay, fuses, switch, and headlights from my 01 2500hd to no avail. I notice that the switch works for the running lights, dome overide and dimmer but the actual switch lights do not work. The funny thing is that I have power to both wires on all four headlight plugs instead of one hot and one ground. I have had the four high conversion on this truck for years but i have just unhooked it thinking that might have been the problem. I am thinking that i have a BCM problem but thought I would run it by you guys to see what your opinions are. Am I missing anything simple or obvious? I hope so!

Thanks , Bill

Bill do your brights work?? Reason I ask is on my 99 Suburban my Multifuctional Switch is bad....and basically when I turn on the headlights via switch they will not work at all, but if the brights are turned on and kept on they will work....My DRL's are my lo-beams...so basically I turn on the Park Lamps when I want Low Beams and the Headlights when I want high....however I bet your truck has Auto Headlights, and also your DRL's aren't your low beams....so I don't know if it'd be the same in your case....however might be something to check...

Bostonsfavson · March 20, 2008

Sounds like maybe you have a bad ground somewhere. I had a similar problem on a Firebird a few years ago; turns out I had some corroded wires in one of the harnesses. Boy, was that a bitch to track down. It could be the switch as well; if you could swap a new switch in and try it, that would be great. I've seen these switches go a few times, and it's a relatively simple and cheap solution to try. Of course the first thing I would do (if you haven't already) is unplug the battery and let it sit for about thirty minutes. It's amazing how many electrical problems this will solve. It's probably the switch or some corroded wires though. Good luck, and keep us posted!

Bukmaster · March 20, 2008

yep, i have auto headlights and my DRL's are separete. I have no high beams and no high beam indicator on the dash. I did swap out the switch on the dash with the one out of my HD but, I have not considered the multifunction switch though. The ground problem had crossed my mind but I didn't give it much consideration because everything else is working. It still might bear looking into though. I did unhook the battery overnight. Come to think of it this problem seems to have occured after I swapped in a new battery, could be a coincidence?

Thanks for the replies,

Bill

badmeds · March 20, 2008

The headlights on my 99 Silverado have quit working. Every other light is working including the fog lights. I have swapped the relay, fuses, switch, and headlights from my 01 2500hd to no avail. I notice that the switch works for the running lights, dome overide and dimmer but the actual switch lights do not work. The funny thing is that I have power to both wires on all four headlight plugs instead of one hot and one ground. I have had the four high conversion on this truck for years but i have just unhooked it thinking that might have been the problem. I am thinking that i have a BCM problem but thought I would run it by you guys to see what your opinions are. Am I missing anything simple or obvious? I hope so!

Thanks , Bill

my 99 (now gone, sniff, sniff) was the same. The headlights actually apply a ground to cause the headlights to come on. My guess would be that the sensor in the dash is bad. Try using the flash to pass function and see if the headlights come on.

Bukmaster · March 22, 2008

No flash to pass and I can't seem to find any wires disturbed that could be causing this issue. it seem to me that since I have power to the relay and the fuses and power to the headlights themselves that I have a control problem. Could the BCM have a headlight problem and still let everything else work properly? I have found a used BCM at a local junk yard for $50. Anyone see a problem using one out of a wrecked truck provided that the numbers match? ANy other suggestions I might be overlooking?

Thanks,Bill

dsbowtie · March 24, 2008

No flash to pass and I can't seem to find any wires disturbed that could be causing this issue. it seem to me that since I have power to the relay and the fuses and power to the headlights themselves that I have a control problem. Could the BCM have a headlight problem and still let everything else work properly? I have found a used BCM at a local junk yard for $50. Anyone see a problem using one out of a wrecked truck provided that the numbers match? ANy other suggestions I might be overlooking?

Thanks,Bill

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A used will need to be programmed for vin#. Your problem is most likely the multi function switch.