924Board.org

[mgatlag]

Well back to messing with the headlight motor again. When I turn on lights, they pop up fine and turn on fine. But when I turn them off, the lights stay up and turn off, leaving the parking lights still on. If I pull the top (of 4) wire from the connector at the headlight motor, they go down fine and parking lights all go off. I've taken apart the connector and cleaned both ends, tightened up the male/female connections and greased her up only to find that I still need to open the hood and pull the wire to make the lights go off and down. Any ideas? Relay is good, as well as all grounds. Oh yea, if I keep that same top wire out of the connector and try to turn on the lights, they don't go up. So it's something with that wire??
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Michael
'77 1/2 924 N/A- 5 speed Audi box
'04 Ford Taurus - gone!!
'92 Jeep Cherokee Laredo - gone!!

Porsche... better than tea with Miss McGill
(Slap Shot)

[Smoothie]

I've no personal experience with this, but '76-'78 have some diodes in the motor. Maybe they're causing the problem..? Try a search for all terms on headlight motor diodes .
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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[Druman]

Sounds to me like a problem inside the switch in your dash, take it apart (if you haven't already done so) and see if everything is connecting correctly.


7osh
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87' 924S non-sunroof (Red) 45K miles
85' 944 "early" NA (Red) 130K miles

PORSCHE pisses excellence...

[mgatlag]

Ok I think I found the issue. Did some reading, reading and more reading and found out what a diode is and kinda what it does. From the looks of mine (umm, melted) that may be the issue. Which makes sense because if I follow the wire that the diode is soldered to, it is the same wire that I'm removing to make the motor go down. So I guess I'm going diode shopping.
I did take off the cover from the gear area and found it to be in almost perfect/new shape. Lots of grease still in there and nothing was corroded at all, so that made me feel good.
So.. Radio Shack? or should I find an electronics shop or some sort? Hopefully I can take in the motor and match up a diode from something they sell.
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Michael
'77 1/2 924 N/A- 5 speed Audi box
'04 Ford Taurus - gone!!
'92 Jeep Cherokee Laredo - gone!!

Porsche... better than tea with Miss McGill
(Slap Shot)

[ideola]

I don't know if there is a wiring issue or not, but I have three headlight motors in my spare parts bin. I think I listed them for sale pretty cheap, so I'd be happy to send one down to you if a later model can be retrofitted on an early car with no issues.
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erstwhile owner of just about every 924 variant ever made

[Druman]

Hey, glad you found your problem, makes ya feel good doesn't it haha.


7osh
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87' 924S non-sunroof (Red) 45K miles
85' 944 "early" NA (Red) 130K miles

PORSCHE pisses excellence...

[RC]

Those diodes are general purpose rectifiers, 1A, 100V, nothing special. Common type # is 1N4001 (1N4004, 1N4007 just higher voltage), or similar. Even Radio Shack should have them if the boy knows what a diode looks like.

These are polarized and must be replaced the correct way around. Ensure the white band is the same way as the old one(s). IIRC they are in opposite directions. Replace both, cheap insurance for 20c.

Roger

[mgatlag]

I was hoping you'd chime in Roger. I went today to Radio Shack and well...the tard behind the counter was less than helpful. Shaniqua didn't know what a diode was. I did find them and they had more choices for me than I wanted to chance spending $ on. Thanks Roger for the #'s I was going to ask for. You beat me to i! I think I will go ahead and change out both of them as you said. I don't wanna do this twice.

Is there a special kind of solder that you recommend? I have a nice gun with a sharp point so I'm good there. Never soldered before, but I can sweat copper very well so it should pretty easy. Thanks for the input.
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Michael
'77 1/2 924 N/A- 5 speed Audi box
'04 Ford Taurus - gone!!
'92 Jeep Cherokee Laredo - gone!!

Porsche... better than tea with Miss McGill
(Slap Shot)

[datatrain]

Before you get that iron hot... Diodes are heat sensitive and can be destroyed with a hot iron. Ensure you heatsink the the leads before you touch the iron to them. Attach an alligator clip or have someone hold them with needle nose pliers to dissapate the heat.

Solder must be hot to run properly and the leads must be at the same temerature to get a good bond. The Diode should be mechanically attached to it's terminals after you've cleaned them, to ensure it wont break off with vibration.

Apply a bit of solder to the iron and then wipe the tip. It should be shiny and run easily. Touch the iron to the joint and apply a little drop of solder to transfer the heat to the joint. When the solder begins to move on the joint then add enough solder to fill the open areas around the connection. Hold the iron there until the wet solder is shiny all over the area. Remove iron and allow to cool.

A proper job will have a smooth and shiny appearance. If it looks frosty do it again.

I would use 60/40 solder if available.

DAve
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'78 924 NA with Collector plate
33 year old car, with me for 21 yrs
Mint '92 318i BMW
Near mint '98 Buick LeSabre
VE7HFR

[RC]

As above, but make sure it is resin cored, electronic grade flux. About 1 to 1.6mm (#20 - 16) diameter is ideal. Any electronics shop or RS will have it. Definitely don`t use plain solder (hardware, radiator, etc) or any type of acid flux.

Ensure the iron is hot and work quickly as it actually transfers less heat than a using a cooler iron for a longer time. Too much heat/time and the plastic base will melt and deform. Suggest some practice first on similar size copper wire to get the hang of it.

Roger

[wombat]

I feel you with this issue, my headlights go up fine but when you go to put them down they continue to cycle down, up down, up down, up down, up down..... up down. this seems to be worse when the car is in on and not so bad when in acc??? I am going to try to clean the contacts and the switch but after that it anyones guess.
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1977 924 2.0 Auto

[Smoothie]

[RC]

These diodes are 3A (increased fudge factor) and physically slightly larger but the connections and orientation are identical.



Replaced these some years ago after one burnt out. From the evidence of meter probes in the solder can deduce that I have subsequent problems. One faulty relay and 1 or 2 cases of intermittent terminal connections. Replacing the rubber cover would help reliability too. For others reading this thread though, first step is to wiggle and R&R the plug and relay. Then check or replace the relay which is a common Bosch or generic part.

It is just the early years that use this diode set up, later wiring differs. The diodes can easily be checked with a multimeter diode function that even cheap ones have these days. The forward voltage should be 0.5-0.7V and zero reversed. For this basic application 99% will be either go/no go. Burnt indicates a short which is more common than open circuit.

Roger

[D Hook]

BTW, that rubber cover that covers the relay and connection is available on ebay for around $12. New.
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'80 924 n/a SOLD

[wombat]