j.kenzie@sbcglobal.net

Hi guys,
I am kind of stumped and frustrated.
I stripped the gears in my headlight motor by leaving the headlight pod cover loose, then lowering the pod, then trying to raise the pod with the cover wedged in place preventing movement. Anyway, I ordered a used motor. I labeled the connections and reconnected the new motor, and it does nothing. Moreover my old motor does nothing, where before it would spin wildly. Furthermore my headlights won't go on anymore. Everything worked perfectly before my stupidity.
So I jumpered my headlight relay 30 to 56a and my lights turn on.
So I got a used relay and my headlights turned on, but shut off after a minute or so. Turned everything off, jumpered the relay and lights still work. Waited a few minutes and the headlights turn on fine again.
Still nothing from the motor. All fuses fine. Headlight switch seems fine: turns on parking lights, instrument lights, and headlights sometimes.
I expected to have immediate action on the headlight motor, either moving to its parked position, or moving to its up position when I turn on the headlights, but I get nothing. No action on the old motor either.
So, my questions are:
1. Is there some circuit in the headlight relay that turns the lights off if the motor does not raise them?
2. Do you think I got a bad headlight motor, and/or a bad headlight relay.
3. Any tests for me to tell?
Sorry for the long post, and thanks for any help.
Dave

j.kenzie@sbcglobal.net

Hi again, guys,
OK, I solved one aspect of the problem. The HL motor grounds through the case, and I did not have it installed (grounded) when tested to its connections. The mounting bolts did not look like a good ground so I assumed the ground was through the connector. Not so. (It's not that easy to get the motor out or in, so I wanted to verify function first.)
Anyway, we are having a snow storm right now, and I had to move my car outside for a day or two, so I cannot try the new motor again installed until then.
I hope installed, all will be well.
Still, why would the new HL relay light the HL's fine for a minute or two, then shut off. Then work fine again after a 5 minute rest? It sounds like a design feature, but also maybe a defect.
Sorry and thanks,
Dave

Mrmerlin

it might have something to do with the motor not being grounded

j.kenzie@sbcglobal.net

Thanks Stan,
My hope is on Friday, I will ground the motor and everything will just work like it should. I think there's a pretty good chance.
Dave

Alan

The relay has no thermal cutout - but it will turn the headlights off whenever it thinks they are not fully up. This is communicated back from the HL motor by a continuity track in the headlight motor that knows where fully up and fully down are. This exact mechanism is different between pre-S4 & S4+ cars.

For Pre-S4 cars this mechanism does not rely on the case ground - it has 3 dedicated connections - but a problem with the connection of either of 2 of these could cause what you have seen. Wiggle the motor connector...?

Alan

j.kenzie@sbcglobal.net

Thanks Alan
The wiring diagram for my 84 shows 4 connections and a case ground. I was able to get the old motor running with +12 and a ground, but no other way.
Dave

j.kenzie@sbcglobal.net

OK, It does ground through the case.
I first jumpered the case to chassis ground, connected the motor, and the new motor went to park position when I turned on the ignition. When I turn on the headlights, the motor turned about 180 degrees and the headhights turned on. I mounted it up, and the headlights go up and turn on, and turn off and go down. So all is well with the new motor, maybe nothing was ever wrong with my HL relay, but now I have a spare.
Hard to believe the ground was through the painted frame, but it seems to be.
BTW, I triple checked my e-clips and I think I am OK.
Thanks for all the input,
Dave

Alan

You misunderstand what I was saying: the motor certainly uses the case ground to run and will not run without it.

The feedback mechanism doesn't use the case ground - it is independent of ground (but obviously it does depend on the motor position).

There are only 3 connections for the feedback circuit - the 4th connection is for the motor drive only.

Alan

BTW S4+ cars are very different - they don't rely on a case ground and have 2 motor connections (since the motor reverses direction) for a total 5 wire connector. The feedback mechanism is a similar idea but differently configured (no diodes).

j.kenzie@sbcglobal.net

That sounds exactly correct, Alan. Sorry I misunderstood.
Thanks,
Dave

uraniummetallurgist

Hi Dave:
Are these the new Cree LED lights that you just installed as per your post on "Cree LED H4 Headlamps"? Maybe there are issues associated with the new wiring harness for the LED conversion? Your first post here mentioned that the lights would not go on and that you jumpered relay 30 to 56a and the lights came on and then they went off. Once you have the motor sorted post back on how your lights are working.

All the best,

Joe

j.kenzie@sbcglobal.net

The Cree LED lights work perfectly with the proper headlight motor connected. If you watch how your headlights turn on, first they raise, and then the contacts in the motor tell the HL relay to turn on the lights. When I goofed up my motor, I defeated that lighting signal, and they did not turn on.
Anyway, with a working HL motor, all is truly plug-and-play, and working perfectly. Any problems were solely of my own doing.
Dave

j.kenzie@sbcglobal.net

PS
The LED has no harness, really, just a 4" pigtail with a light socket. This makes room in the HL pod, since the rear of the LED light is a little bulkier than stock.
D.

uraniummetallurgist

Thanks Dave.
The harness I was referring to is the power supply for the LEDs and cooling fan that mates up with light/fan on one end via the pigtail and the power from the car at the other with the 3-prong receptacle. Looks like quite a bit of kit to be packed in the HL pod.