2002 Silverado Truck No Headlights and question about no start problem Options Options

Hello again So heres the deal (NO Ground to low beams) I went out with my multimeter in hand today and found that the headlights have no ground on the lowbeams now my most logical thought was to just splice in a new ground, so I figured the highbeam ground was very close so why not use that (Right?) Wrong I was then suprised to learn that when I spliced into the high beam ground wire and tried the lowbeams all the headlights now came on high and low beams . So I figured that the grounds must run through a relay of some sort at this point so I disconnected the splice I made and it is back to a no headlight on low beams. But here is my question can I just run a new ground wire spliced into the lowbeam ground wire and ground it to the body of truck (because lowbeams will work when grounded to the body I tested it and yes they worked as they should (but I thought the wire I was using got a lil hot so I did not leave it connected to long). Or are these headlights designed by GM to be grounded only through a relay to avoid burnout? Or can I go ahaed and just use the spliced in ground and use the low beams safely the way the new ground is? Thanks again for all who respond

Reply to
imatoolman
Loading thread data ...

I have tracked the problem to the low beam ground But can not for the life of me trace the ground back to it point of oringin. I was wondering if I could just jump in a new ground off the frame of the truck? I did a test wiring for a temp ground wire and the headlights worked fine I am just nervous about jumping in a direct ground just in case like you said there is 1/2 voltage involved. But when I placed a volt meter to the positive lead to the bulb and then ground the other lead to the frame and I did get 11.79 volts (12v lets say correct) I can not see why I can not just replce the ground wire at this point I would cut the old wire and install a new ground and see what happens \ any ideas Thanks again

Reply to
imatoolman

The computer probably grounds them to turn them on/ maybe for just auto? I don't know.

Do the auto headlights work with your ground the way you have it? Does it work completely normally?

Reply to
ScottM

11.79 volts is not 12 volts, and true battery voltage should be over 12.5v I believe unless you fully understand the headlight circuitry it would be a vary bad idea to start cutting wires or bypassing things. If the headlight circuit is controlled through the computer then you must diagnose the problem correctly. I would strongly suggest having someone who knows the system check it out. Cutting wires on any post 2000 vehicle is a very bad idea. A technician familiar with the vehicle will likely track the issue in short order.
Reply to
Battleax

The ground may be what is switched by the comp. Although I don't recommend you mess with it, one back yard mechanic diagnostic step would be to provide a chassis ground to the ground lug on the headlight low beam plug while the vehicle is off. If the headlamp illuminates this would show that indeed the ground is switched on and off and not the hot.

Reply to
Meat Plow

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.