Headlight Problems
 

Hey guys , just a quick question with a problem I am having. My headlights are not working on my 68' GMC. I tested them by putting my tester on the ground side of the battery and used the other end in the socket. Nothing, I pulled the switch on and off and again nothing changed.
Then I put my tester on the negative side of the battery and when I put the other end in the sockets they lit up but still nothing changed when I turned on and off the switch.
where do you think I might start? thx everyone

Re: Headlight Problems
 

Cycle the dimmer switch many times with the lights on. I'll bet they come on. The dimmer contacts get dirty.

Re: Headlight Problems
 

The floor mounted dimmer in the cab. Take the center wire loose and put your test light in the wire connector you took loose. Turn on the head lights. It should have power.
If it does your good to the dimmer, if it doesn't then the problem is in that wire some place.

If you have power plug it back to the dimmer and take one of the other connections loose and try activating the dimmer to see if it lights up. If it doesn't then your dimmer is bad. It could just be one side bad but either way you will need to change it.
If it does light up then move out to the drivers side head light and unplug it. The head lights all get 12 volts at the drivers side bulb. At least Chevy's do so I would think GMC do also. So check it first.:chevy: