daddyw

I have a 88 Vette and I just got through installing a set of Delrin bushings in the left side headlight motor. Replaced the right side in 2015.

Re-installed headlight unit by turning the **** on the motor, it operates perfectly. Turn light switch on headlight lights up but the motor does not rotate. Checked feed wires to the motor which are grey and green and there is no current, the right side operates normally. I ran two wires from the battery to the motor terminal and Bingo the motor opened the headlight assembly, switch wires and it closes the unit.

How do I locate what is causing current shortage?

Any help would be greatly appreciated.

antfarmer2

This sounds like a current or ground problem on that side. Check the connection on top of the side marker light that goes to the motor and the ground.Trace the wires back. Did you take a ground off and forget it? Try swapping the relays.

Kevova

Check fuse for left head lamp motor

Hot Rod Roy

There are no relays in the '88 headlight motor circuit.

antfarmer2

Thank you always learning no help for the poster?

Hot Rod Roy

If I'm not 100% confident that I have the right response for the question, I keep my mouth closed.

ChumpVette

Hook up a test light between the two terminals and see if you have light when opening or closing the headlights. Next step is to check continuity of those green and grey widest other connector (Terminal C and D) at the headlight control module at the left front of the fender well.if continuity checks out, your headlight module has gone kaput.

antfarmer2

But yet you always find time with your little buddy to try to insult me for trying to help. the point of a forum is to exchange thoughts and ideas so all can learn. Not to stand on your little soap box trying to **** on everyone not up to YOUR standards. LMAO

Hot Rod Roy

So you think bad advice is helpful? I was being nice to you!

antfarmer2

TRY........ Reading my post........... And how is trolling me helping the OP. Stop highjacking OP posts for your petty games.

Scantool_Guy

I think you have the same problem, that I just resolved. I came home late from work put my car away. Next morning I came out and found my headlights up. At first, I thought I left the lights on and the battery was dead. But no for some reason the headlights were no longer rotating up and down. I started diagnosis at the headlight control module.
Good powers, good grounds, and the two signal wires changing to 12+ when the headlight switch is turned on and off. On the headlight motor side nothing. OK the module is dead, I tried for a month to find one. The best I could find was NOS from a dealer for 500 bucks. So I pulled it out of the car and break into the module (the back comes off). I saw the problem right away. The smoke haze in the relay case and broken wire to one of the contacts caused the control to stop working. a little online searching, I found a replacement relay and ordered 2, I also ordered replacement mosfet's since they can get stuck on and cause a short to ground blowing fuses and overloading relay contacts.
Put in the new relay and mosfets, reinstalled in the car. Both headlights rotate closed, but only the left rotates back up. The right side is dead. I quick search on the right side and I find the problem, the green wire has a worn spot and created a short to ground. When the headlight switch is turned on, 12+ is applied to the wire, the amperage exceeds the 5 amp current max. of the relay and the contact fails. So I taped up the wire, replaced the relay again (good thing I bought 2) and it is fixed. Less than 100 bucks in parts. Done.