I'm confused as to how the headlights are wired on these cars. The one that works is only getting 12v at one pin, no matter whether the position is in hi beam or low, and the headlight does change beams. My other headlight is getting 12V at two pins, and is wicked dim. I'm assuming it's a ground that crapped out, but I don't know where they ground. I need a wiring diagram or something to help me.

Your deduction is correct about the bad ground. The headlights are grounded through the light switch. There are relays also to provide power to the lights under the dash but since you are getting 12 volts to the light then it would seem they are ok.

 

To prove out the bad ground you could try grounding the lead on the light socket. There should be three leads tied to the socket. The middle on ties to power. The other leads go to ground through the switch. By manually grounding the outside leads it should turn on the lights.

 

If you tell me which side is having trouble I can provide you with some with colors to look for.

It's the front right one. It started after a decent wheeling trip with the bow wave breaking on the windshield... so i'm wondering if the water affected something.

 

Tommorow morning between class I'll give you the wire colors and what I'm getting from them on both sides.

My first recommendation would be to remove the connection to the head light and make sure the contacts or clean and tight. I think the problem may be right there since it is a common trouble point. If that doesn't work then check the red/wht and red/blk wires at the switch. You can ground those wires and see if that makes the lights brighter. If it does, then the swich is the trouble. If it remains the same then there is a problem in the wiring between there and the lights.

I've seen single dim headlights caused by bad relays. Easy enough to swap them and see... Otherwise probably a ground.

 

GD