Headlights don't move

jvandyke

jvandyke

True Classic
After a bit of research I'm ready to look into this. Been driving the car more and more and manually operating the headlights is a pain.
I have voltage (10.9) at the yellow and black wire which I believe feeds the motor. Does that mean the relays and fuses are good and I should pull the motors and check diodes?
 
99% of the time its the diodes. Its an easy fix. The diodes are pennies a piece. I fixed both my motors in 15 minutes.
 
I fought and fought with my headlights for the longest time. The lights worked, but they wouldn't go up. If I rotated the motors by hand they would cycle at a certain point, but that's all. Replaced the diodes, did everything I could think of. Except check the fuses. That's right, one was missing. :wall::wall::wall: They sure worked good after that! Stupid should be painful.
 
I have voltage (10.9) at the yellow and black wire which I believe feeds the motor
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I don't see YLW/BLK in either of my wiring diagrams, maybe you can tell us a bit more about where this wire is.

There are three relays related to the headlight motors: Right motor relay, left motor relay and one "parking lights and concealed headlight control" relay. What you can do for a test is to remove the left or the right headlight motor relay and jumper terminal 30 to terminal 87 (and be sure to jump the correct terminals, or you could blow fuses). This applies power directly to the motor, bypassing all the control circuitry. It should get the motor moving regardless of the state of the diodes. If the motor turns, then go on to check diodes.

Generic Bosch relay pin numbering:
relay.gif
 
ng_randolph said:
I don't see YLW/BLK in either of my wiring diagrams, maybe you can tell us a bit more about where this wire is.
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What I did was reach down and feel which wires were going to the motor (driver's side), followed them up found the connector that went to them, yellow/black the other black to ground cluster. I think the same wires on the passenger side are yellow without black in tandem with a ground. I turned on ignition and lights and there was voltage there. There is another set of wires going down to the motor but I didn't check those yet.
Jeff N., I think I stumbled across an old post of yours about the fuse thing and I eyeballed all fuses and pulled and reset all relays but nothing appeared amiss there at all. I'm going to pick up the diodes today and attack this tonight. I almost took the Fiat in for the commute today but backed up as I'm still a bit leary of "making it". All test drives all weekend were fine but, well, 3 or 4 miles hops are one thing, 20 miles in morning rush hour with a job (needing prompt attendance) at the other end, well, let's just wait a day or two more.
I also have no door key and one of my job sites is in a nasty part of town where vandalism is known. Not comforting.

headlightwiring.jpg
 
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Disregard the earlier post on yellow wires and such, I thought they went to the motors but I think they go to marker lights or something....

Pulled motors (BTW this is wrong, go by the manual and undo the linkage to the headlight FIRST, then the three mounting bolts, also it's 1N4001, no 1N400)

I tested diodes as told in another thread, they check out fine (AFAIK)
My ohm meter reads 580ish on all four when the negative probe is on the motor lug side of the diode, positive probe on the incoming wire side of the diode. This matches the new diodes (they read 580 aslo). I guess I won't redo the diodes than.
Hmmmm was hoping that was it.....will go reinstall motors and start looking elsewhere.
 
I'd suggest trying the jumper test I mentioned in my previous post. This applies power directly to the motors, bypassing the ignition switch, light switch, diodes, diverter relay etc. You can do this with the ignition off and the headlight switch off. If you do this, you should see the headlight going continuously up and down until you remove the jumper. Fuses I ( left headlight) and K (right headlight) must be intact for this to work.

Do your tail lights / parking lights work with the light switch in both the "Park" and "Full" position? (Ignition on for this test!) If not, the fault is likely in the light switch. If park/tail light work as they should, I'd be suspicious of relay E2. You can test this by swapping in relay E3 or E5 into the E2 location.

The headlight motor circuit takes a bit of concentration to understand. I found it helpful to redraw the wiring diagram in a way that is easier for me to read:

HEADLIGHTS.png
 
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Okay thanks. I'll take the above advice and report back. I had a heck of time putting the right motor back in. Finally figured out if I get IN THE TRUNK, I can do it easier. Cute.
 
budgetzagato said:
Hey Jeff,

Start at the beginning and check the output of the ignition switch. The black wire powers the headlights, the blue wire powers motor relays, heaters, etc... Do other key-on accessories work?
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So I can start by probing the blue wire as it exits the ignition switch. With the key set to "on" I should see voltage. I imagine there is a place to check where the blue wire enters the fuse/relay nest too. Heater blower works fine, don't know what other accessories to check but if the heater blower works off this blue, then can I assume that is good?

I will try the relay terminal jump.
All running lights, tail and parking work in both Park and Full positions.
I'll try swapping relays E3 or E5 into E2. Although parking lights work and I think E2 controls those too.....
 
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Oh Jeff...

Did ya REMOVE the LAMPS first?

If ya do that... then ya can reach right though the BIG holes and easily reach most of the mounts and linkage. Then reinstall the lamps AFTER ya get the doors working properly.

(Sorry I didn't menton this earlier... but it took me about 15 years before I thought of it myself...)
 
Black-Tooth said:
Did ya REMOVE the LAMPS first?

If ya do that... then ya can reach right though the BIG holes and easily reach most of the mounts and linkage. Then reinstall the lamps AFTER ya get the doors working properly.

(Sorry I didn't menton this earlier... but it took me about 15 years before I thought of it myself...)
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Of course not, if you didn't think of it for 15 years, I sure wouldn't have in 30 days.:lol:
 
Although parking lights work and I think E2 controls those too.....
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The relay description in the wiring diagram hints at E2 controlling the parking lights, but it actually does not. It controls the opening and closing of the headlights based the state of the light switch and the ignition switch.

The ignition switch has two outputs that are on in both run and start. One of these is used for most of the lighting, the other for almost everything else. So, if you car starts and runs and the lights work (aside from opening/closing), then the ignition switch is not a likely culprit.

Except of course that you have an '81 and my experience is with an '85. Although I think apart from a different fuse box, the wiring is much the same between the two.
 
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hmmmm swapping relays around; no effect
jumping terminals: no effect
I do see some wire nuts in the rat's nest. I don't Fiat used those....will try to find camera back.
 
You just ruled out a whole bunch of possible problems.

The wire that brings power to the motor should be green (according to my wiring diagrams). Same color for both sides. This wire goes to one side of a two-pin connector in the head lights pod. If you measure voltage at these wires with a jumper in place of each relay, do you see voltage?
 
There are two two pin connectors at each motor as I remember from last night. Perhaps they got swapped? I tried to put them back as I found them but who knows if I found them correct or not.
 
So I reversed those two two pins. Guess what. Lights move. They move opposite of each other and don't stop, but they move. Is that progress?

I manually turned them to match, they now rise and lower together, they just won't stop going up and down. Unintentional winky mod?
I now have green and green with a white stripe going to the white connector off the motors and brown and light brown going to the black one. Interesting. It made my 9 year old laugh. That's something anyway.
 
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No synchronization needed

I'll check the wire colors on mine when I get home (~1 hour). Perhaps even post a photo or two. The two pods do not need to be synchronized.

If you remove relay E3, does one light stop moving? If you remove relay E5, does the other light stop moving? Removing these relays should make the headlights not move, if that is not the case, the wiring is wrong.

Did you say you measured the diodes and found them to be good?
 
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