Problem number two both headlights come up.. one only goes down

D

duderduderini

True Classic
Hey
Its laughable really.. I checked these babys for months and every time they worked flawlessly.. anyway today just before the carby problem the left front headlight goes up but dont go down.. I checked the fuse wiggled wires etct etc to no avail. Since i know onlky enough about electrics to get myself in trouble does anyone know of a diagnostic procedure I can try to isolate and fix this problem

Thanks
 
Sounds like a bad or broken diode

Unfortunately not easy to get to without removing the motor, but that's likely what you've got to do anyway.
Spare headlight motors are cheap and easy to get these days, but they are easily repaired if it's a bad diode.
There are 2 on each motor.
 
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As Bob says... but FIRST...

Verify all your GROUNDS are good at the BLOSSUMS... and the blossums are good to the car. (That would be all the BLACK wiring from the bulbs and motors to the chassis)

You'll need to learn some basic electrical theory and skills with a VOM or find a good friend locally that has some.

HTH...
 
Thanks

I will begin to deal with this once i sort the carby.
Bob are the diodes easy to get to and which type are they?
Nick
 
Easy to get...

go to any electronic supplier and get a couple of:
1N4001 (50V) or 1N4002. (100V) They're cheap.

Here's 10 of them for 2 bucks, delivered to your door HERE:
 
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Thanks Bob

Hi and thanks. What self respecting geek doesnt already have the aforementioned diodes in his kit at home you may well ask?
I have them.
Back to the topic of the motor.. it seems to work fine so other than diodes if the brushes and bushings look ok then there isnt much to refurbish?.
Bob is there a thread that describes dismantling the motor?
Many thanks to those that helped
Nick
 
You might already have this, but in case you don't...

http://homepage.mac.com/jvandyke/Ele...sticManual.pdf

Jeff is hosting this document and has made it available for the X-web community in an earlier post. Had to do a bit of a search to dig it up. At any rate, if you don't already have this on your HD, I would suggest downloading it (right-click, save as) and checking out page 29. ((WARNING - it's not a small file!)) Explains how the whole circuit works. While it doesn't have a good (ok, it's non-existant) troubleshooting procedure for the headlight pods, it does give you a good place to start.

The reason I bring this up is that I've had a headlight switch fail and it did some REALLY goofy things during its death-throes. The lights would come on but not lift. They would come up but not on. They would come up and on, then turn off but not go down - or go down and not turn off. And it all seemed to depend on what THEY wanted to do at any given time. Sometimes they would do their own thing individually, but mostly as a pair. I rebuilt the switch (at the same time as doing a bunch of relay mods) and that was that. I'm not saying that this is going to be what solves your problem, but there might be a few things to check out before rebuilding the motors and replacing the diodes...
 
I will check the grounds I promise

Hi Tony'
I heed your advice to check the grounds and will. To everyone else thanks and i will let you know what gives
Nick
ps the file wasnt so big and thanks
 
Great Nick... I hate ta see ya go through...

... all that trouble replacing diodes and then NOT have it be the problem!

We'll be right here waiting...
 
WOW Dave... that's a keeper...

... and its for an 80 - 81 so its good for both Carbed and FI models.

Maybe not an EXACT science for other years, but a good "ballpark" reference book to have!
 
Grounding quirks.

Too many years ago I found out how bad lighting can work without a good ground. When checking out utility trailers for myself and friends a bad ground in the system would cause the lights to really get mixed up. Brake, park, and signal would be mixed up and partial lighting on some etc. Who would think.
 
Trailers, campers, boats, hooray, hooray!

Yep...

Folks fergit that the GROUND is simply the other HALF of the circuit!

When it comes to trailers, I always run a separate lead and never rely on the hitch alone.
 
Headlight Fixed

Hey Guys
I checked, rechecked everything that was suggested. I decided to remove the headlight motor and found a very rusty/almost broken off supply wire to the diode (the green one) The diodes were easy to get off as the just disintegrated as i desoldered and pulled out with my tweezers. I didnt have any waterproofing goo to place over the new connections so I dripped candle wax over them (how ode worlde is that)
and bingo the light pod retracts.. only problem is that it raises and lowers quicker than the other one now so I will have to do that one too.
This was an easy repair to do.. i was prepared for another "fight" but it was really straightforward. Hey Bob I have 50 4004's in my geek room.. you cant have too many of them sitting around.
Anyone have a diagram to aim the headlights?
Nick
 
Well Nick, glad you found it

I figured from your description it'd be a diode. Glad you found it.
As for the 50 of 1N4004's you have, maybe you can offer them to other exxies in trouble?
I've got plenty kicking around my workroom but my problem is finding them... :nuts:
 
Noooo... Bob! I get the credit for this one!

The bad diode was the EFFECT of a corroded wire which was the CAUSE of its excessive current draw!

And I'm even MORE glad-er he found it!

HA!

I believe that's TWO donuts he owes me now...
 
Glad to hear...

Glad you fixed it.

So, I have one headlight that raises and lowers just slightly slower than the other, could this be diodes as well?

Want to send me enough to do mine? I'll gladly pay for them and the postage.

Thanks.
 
Well Tony, You'd like to think so but

Your post reaction time is getting a little SLOW in your OLD AGE! Ha!
Better luck next time! :guitar:
 
Similar function on my '78, Greg.......!!

budgetzagato said:
.....I have one headlight that raises and lowers just slightly slower than the other, could this be diodes as well?....
Click to expand...

.......but I would think that a bad diode would not allow the h/light motor to work at all, not just slower than the other one. (Hey, I'm only guessing here, I'm certainly NOT an electrical guru!)

If you get around to fixing this little problem with a diode change, I'll be the next in line to do similar! ;)

I have found that by squirting a bit of CRC/WD 40 on the h/light lift linkage from time to time, it "seems" to improve the speed of the slower lift motor's function FOR A SHORT TIME. It soon reverts back to that lazy "wink" again tho!

cheers, Ian - NZ
 
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