Headlight/Foglight Issue...Need Advice

[997at]

1982 SC US car. Came from the factory with fog lights. Last time I drove the car before today all of the lights were functioning perfectly. Today, I pulled the headlight switch on and only the passenger side headlight came on. I then pulled the fog light switch and no fog lights came on. Then I tried the high beams and they're not working either no matter which direction I pull the turn lever. Turn signals work fine and parking lights are fine.
I haven't checked the fuses yet. My search did turn up the turn signal issue thing, but this seems like a different set of issues?
Any advice appreciated.

[997at]

OP here. Just checking in to see if anyone has experienced anything like this before? Otherwise I think I'll have to systematically go step by step through electricals and switches.

[997at]

Hi All. No responses to my posts on this, so I'll keep taking to myself through this thread as I troubleshoot. In case I figure it out this might eventually help someone else down the road.
So I checked all of the fuses and relays...all good. Next I checked the drivers side headlight...the bulb was broken. It's a sugar scoop sealed beam halogen. I'll order new headlights for both sides...likely sugar scoop H4s. Once I have the new headlights in I'll see if the high beams and fog lights are still not working. If not, I'll move on to testing for current at various junction points. It's possible that the turn signal switch thingy is a culprit but not sure how that would affect the fog lights. I do know that for US cars, if the low beams aren't working then your fog lights won't work. I'm just not sure if fog lights are affected if only one headlight is out.
Will keep everyone posted as I work through this.

[997at]

Just thought I'd post a quick update as I continue working through these issues. Got two new Hella H4 headlights (sugar scoop style) and the headlights are all good. Tried high beams and fogs...both are still not working.
Next step is to start checking along the high beam and fog light circuit junction points (fuses, relays, switches) for voltage. Hope to do that this weekend and will post results. I have a suspicion that the turn signal/dimmer switch assembly is the culprit for the high beams but possibly the fog lights as well if power is sent to the fog lights through this switch (not sure if it is but I will find out shortly).

[Cairo94507]

On our old Porsches, having clean grounds is critical as well as making sure all of the bulb sockets are nice and clean. I like to use dielectric grease when I install a bulb. Of course, fuses and relays are another likely culprit to lighting problems. Good luck with your fix.

[ChrisHoover]

Garage Time on youtube just did a video on fog lights a few weeks ago. Might check it out.

[PeteKz]

Just seeing this thread. Same comment as Cairo. Make sure your connections are clean and tight. Since it affects several lights, I think a bad ground connection is likely. As long as you are doing this work, consider installing headlight and foglight relays to take the high current off the switches. If you plan to substitute LED headlights or foglight, then the current is much lower and relays are not necessary (but nice to have).

[targa80]

Originally Posted by 997at

Just thought I'd post a quick update as I continue working through these issues. Got two new Hella H4 headlights (sugar scoop style) and the headlights are all good. Tried high beams and fogs...both are still not working.
Next step is to start checking along the high beam and fog light circuit junction points (fuses, relays, switches) for voltage. Hope to do that this weekend and will post results. I have a suspicion that the turn signal/dimmer switch assembly is the culprit for the high beams but possibly the fog lights as well if power is sent to the fog lights through this switch (not sure if it is but I will find out shortly).

Do you have a schematic of the wiring to use while troubleshooting with a multimeter? I would suggest troubleshooting one issue at a time.

Assuming high beam fuses 7, 8, and low beam fuses 5 & 6 are good.

High beams:

With ignition off, pull the dimmer/flasher/turn signal switch towards the steering wheel. The high beams should come on while holding the dimmer/flasher/turn signal switch towards the steering wheel. If they do not then t/s the unswitched voltage line at terminal 30 (rd/wt wire) of the dimmer/flasher/turn signal switch. This wire is a unswitched voltage feed from the battery via terminals 30 of the light and ignition switch.

If the above test is working :

Next turn ignition to on and pull headlight switch to fully on. Headlight low beams should come on. Pull dimmer/flasher/turn signal switch toward steering wheel. The low beams should stay on and the high beams will turn on as long as you pull on the dimmer/flasher/turn signal switch. Release dimmer/flasher/turn signal switch. Next, Push the dimmer/flasher/turn signal switch away from steering wheel. The low beams will turn off and high beams will turn on. If this test does not work then t/s switched voltage source on terminal 56 of dimmer/flasher/turn signal switch. The switched voltage source terminal 56 comes from terminal 56 on light switch via terminal 75 input. Light switch terminal 75 input comes from terminal X on ignition switch.


Once you have the high beam issue fixed then you can look at the fog light issue