Headlight Problem

WildWilly

True Classic
This may have been answered before, so please forgive me. I've searched and can't really find anything on this. My headlights will come up but I can't get them to go down. Where do I start to figure this out?? As always, thanks...
 
There is a diode that goes bad

Had one do the same thing and it turned out to be that diode. Other things may be the cause as well. For instance my left light stayed up recently but when I switched a couple more times the motor was able to chew through the wires it had snagged in the light well... number one rule in electronics if you are working on them and a new problem develops almost certainly is a result of something you touched... I am not pouring over the print right now but I think most of the wiring if bad would cause both buckets to not function... the diode is unique to each motor so a fairly good start point and easy to check and replace. Not super common for me as I have only seen this once in 36 years of Xing. Hope this helps!
Regards
 
Dan's right

Reread your post... if both buckets are not working the common point could be relay or fuse. For the strangest thing I have ever seen my '79 had several relays that were bad... relays are pretty tough so they don't fail that much. There is an up relay and a down relay and as Dan said fuses for each. You might make sure the grounds are good as well... but that takes you out of the single cause area as each motor has its own ground in different light bays. You know the rocker switch is a weak spot as well. My 80's headlight switch failed within the first year of ownership.
Regards
 
Try reseating or swapping the relays. If they now won't go up but do go down, you have a bad relay. Often just reseating or swapping them will solve the problem. It did for me!
Ed
 
Dan, mike from Easton. . My x today my headlights were working, but they came up this am and wont go down. Headlights don't light up at all now. All other lights ok. Could it be headlight motor fuse? Its an 81 park lights work. I don't like the feel of the dash rocker switch. Any idea where I start to diagnose problem?
 
I would think start at the head light switch as it sounds like it is only going to the park light position on the electrical side.

And you did say you don't like the feel of the switch (even more reason to start there)
 
Looks like...

Four fuses handle the beams and two fuses handle the motors. If you feel something weird about the rocker switch that would be my start point... I just had mine apart and the contacts can get messed up. Pretty easy to get apart just tricky. You have a catch on each corner to release once they are free the switch chassis will slide out. You have two little see-saw looking brass pieces with two contacts on one side and one contact on the other. They are the same piece but they point in opposite directions in the switch lift the rocker off carefully as the two spring loaded rods on bottom of rocker hold the contact pieces in their rests when assembled. If the rod on the bottom of rocker are messed up they would not make the proper contacts. If the contacts are dirty or burned and not making good contact that would cause a problem as well. Too late for me to go over print but the switch would be a common point vs a fuse which would require multi failure for your problem. Good luck
Regards
 
The first thing would be to check all of the fuses and relays that pertain to the headlight system, meaning both the lights and the motors.

If these check out OK, the next most common fail point are the diodes in the headlight motors.

If these check out OK, then your suspicion of the switch (which is the only common fail point if both the lighting and motors all went bad at the same time) is warranted. Rod and Rocco seem to agree so I am in good company!:dance:

I do not recall seeing a post that does an autopsy of the mid-late striped rounded rocker headlight switch, which IIRC you would have on an '81.

If you need one, Chris Obert has them in stock at the moment:
http://www.fiatplus.com/1979-82-HEAD-LAMP-SWITCH.html
 
Relays

I have had a look and there are two relays on each side of the car, which ones are for motors for up and down? I found the up relay to be the rear one on the left side, just wondering if the down one is on the other side. I can flick the switch while touching the up relay and feel it click, was wanting to do the same with the down relay. Thx.
 
Back
Top