Let me start off by saying I have scoured over a bunch of threads over the last couple weeks looking for similar issues and such and still dont have a final answer on what I am looking at.
The issue:
Headlights turn on, Lights pop up or one or the other pops up "depending on which module I plug in"
module 1. Original module from car with 66000 miles. Had it resoldered. Looks to be in good shape now. Both lights down, turn on both lights come up. Turn off, right light goes down left does nothing. It will do this each and every time. If I crank the left light down, it will repeat with both lights coming up.
Module 2: A reconditioned module bought from west coast auto parts. Left light will come up right nothing. Or both come up. varies. Neither light will go down.

Both headlight motors are updated with cnc gears vs the plastic and rebuilt by a guy who does these by the 100's. Both lights can be manually cranked up or down with zero issue. The lights turn on each time, the only issue is the motors actuating to pop them up or down.
I have not replaced the switch in the car but it does not appear to be an issue.

What am I missing? Where are the relays by the lights where I can check voltage? Please dont show me a picture of the wiring harness, that is not a language my brain can speak lol. I am almost certain that both modules are perfectly fine that the issue is elsewhere, but short of trying either module in another car I cannot 100% rule them out.

 

Hi nomadicdogg ,

First and foremost , since you mention having a headlight module , there are no relays near the headlights , the module replaced the external relays entirely and has a couple of small relays mounted within itself .

Now , as to your actual problem , the short answer is that I believe you DO have two bad modules , , , and if your interested in why I say this here's why ;

From your description of both module's operation (or lack thereof) , we can safely say that the car is properly commanding the open / close functions as you say one module will open at least one light and one module will close at least one light . Now , since there are no separate open / close functions in the car's wiring for each light other than the module itself (and of course the two motors with their wiring connecting them to the module) one must conclude that each module is flawed in a slightly different way . You say you don't understand wiring and not to post the schematic , well , yeah man I'm gonna go there , I'm posting the headlight door schematic for you to see just how darned easy it is to understand the circuit . Look at the diagram below for the headlight door module and disregard all the other wiring and you'll see that the module has only 9 wires connecting to it , two red ones that give it +12V power , one black one that gives it a negative ground connection , four going to the motors themselves , leaving two control wires , the white and yellow coming from the headlight switch . Those two wires control the module , when you turn the headlight switch on the yellow wire gets power and tells the module to lift both lights . when you shut the headlight switch off the yellow wire looses power and the white wire is switched on , telling the module to close both lights .

PS , since you didn't say what year your car is I went with the 1989 first design module . The module got a slight redesign at sometime after 1989 and didn't have the white wire (and has a brown wire instead fed from the parking lights portion of the headlight switch) , but the functionality otherwise was pretty much the same with the early one . The small wiring difference is of course what makes the modules not interchangeable .....

 

I understand wiring but the schematic loses me Lol. I've wired plenty of cars and houses so its not lost on me but the diagram is if that makes sense.
car is a 1990 so has the brown wires. You answered what I did not know, I was looking for another relay of some sort that could be in the mix. I need to dive in with my tester some more but if say its a safe bet to return the module I bought that was supposed to be reconditioned. Thank you very much for the info