Replacing Headlight Motor Diodes

ryan

ryan

True Classic
I was going through the FAQ on replacing the headlight motor diodes, and coming up with a plan to proceed.

http://www.visualimpressions.ca/fiat/diodes.htm

I had a few questions for those who have tried this before. First one, is it difficult to pull out the two motors? Second question was where can I find these "1N400" diodes? Checked on eBay and on Radio Shack's website without any luck.

Anyway, assuming I can find diodes, any suggestions on soldering in the new components? Type of solder to use? Surface prep?

thanks a lot. I really dislike electronics... :help:

-ryan
 
Many years ago when I had my first X I had to replace the headlight diodes... I just used some general purpose rectifier types... 1N4003 or 1N4004 which are still available at my local Rat Shack for about 99 cents a peice. They lasted years, and were still working fine when I sold the car. I remember the procedure as being quite straight forward.
 
It is very simple, the motors can be removed by taking the lever arm off and unbolting from the bulkhead. When I did mine I had the headlight asy removed anyway so I could reach in from the front... This made it very easy.

BE CAREFUL WHEN REMOVING THE E CLIPS THAT HOLD THE LEVER ARM, THEY ILL PING OFF AND NEVER BE FOUND!

Soldering the new diodes is fairly simple, just regular solder and a basic soldering iron will do.

Regarding the diodes, I'm in the UK so Maplins had them. If you are still struggling then I will look up the codes on them, maybe you can get them online somewhere...

Good luck,
Iain
 
Jim's right, but the number

of Diode you should use is 1N4001. This is a 50V 1 amp diode.
Technically speaking, you could use 1N4002 thru 1N4005 (a 1000 v diode) but load loss and response time is better if you use a diode that is rated closer to your operating voltage.

These are usually cheap-cheap. Look at item # 320305849175 on eBay.
 
My local radio shack had them for $.99, but I went to a local electronic shop and got them for $.35c each.
 
So the correct diode to use is the 1N4001, not the 1N400 mentioned in that online article? I wonder if we can make a note in the original FAQ about that. Though, I think everyone comes on here to ask for :help: first. :)
 
Ok, I'm going to give it a shot and try to start taking things apart tonight if it isn't too cold in the parking structure. :whistle:

We Fry's electronics here, so I'll try to drop by this evening to look into a pen soldering iron, some solder, and some diodes. :excited:
 
These look like the correct bit to buy, eh?

http://www.radioshack.com/product/index.jsp?productId=2036268

I refreshed my memory on electric circuits and remembered that diodes are a one-way check valve for current.

Just out of curiosity, does anyone know why these motors have two diodes on them and what their purpose is? What failure in the diode(s) would cause the headlight to lift fine, but not retract?

thanks!
-ryan
 
One last follow-up on this before I pull the motor this weekend.

So for this case where both headlights open up but the driver side doesn't close, is it most often the case it is a bad diode?

The car had problems with this DS motor for years, until finally it decided it would no longer close the headlight, no matter how many times you switched on and off the lights.
 
I just did mine..

It is easy once the motors are pulled. I replaced mine last night. Very easy process and took about 30 minutes. Thanks to Xana for the help!

Tony
 
Pull the motor.

It is likely to be the diodes but even if it isnt, it will give you a chance to inspect the motor/replace it if necessary and clean up the terminals...

Iain
 
Sounds awesome Tony. :)

I feel excited to try the modification so the headlights stay closed when the parking lights are turned on as well. It never made sense to me why the headlights had to pop up if not turned on. Federal reg?
 
follow up

quick follow up on this, as I'm pretty closed to getting the diodes and equipment to do the repair.

the instructions on the FAQ talk about securing the new diodes using "shoe goo". is that what most who have attempted this repair found good to use?

thanks,
-ryan
 
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