I recently did the conversion to use the fog lights independently of the headlights. Last week I installed new LED Headlights and all Hell broke out.... basically, depending on if the Headlights were in high beam mode and then turned the lights off completely, my Headlights started an unending dance. They just started going up and down all by themselves. When I initiated the high beam switch they stopped. All switches were already in the off position.
I put my original lights back in and operation was normal.
Can anyone tell me what happened and how to work around this issue?
I have a 1972 914-4 which I bought new in 1972.

Which headlights did you use? Some require a ballast resistor or some elec help to balance the voltage draw so that the system knows they are installed. Old v new, you have to help out the old stuff sometime.

You should post a video of that before you fix it. Sounds like fun. Like Tesla celebration mode!

I also have a 1972 and interestingly i replaced all my instrument lighting with led . I knew you couldnt use an led in the alternator light position but after hours of chasing down my no foglight problem i re installed my incandesent bulb in my high beam indicator and all problems went away . These early german cars rely on backfeed resistance for these relays to function . You need to put it back the way is was or add enough resisters to fool the backfeed deal and that may take some doing . Good luck

Okay, I will post a video, but will wait to reinstall until I can find the remedy. I am sure it will entertain you,, it is funny.
The LEDs came from 914Rubber. Will talk to them to see if they can help.
Thanks.

[quote name='L97g' date='Oct 15 2021, 04:38 PM' post='2952807']
[quote name='Jgmarthaler' post='2952803' date='Oct 15 2021, 05:26 PM']
I recently did the conversion to use the fog lights independently of the headlights. Last week I installed new LED Headlights and all Hell broke out.... basically, depending on if the Headlights were in high beam mode and then turned the lights off completely, my Headlights started an unending dance. They just started going up and down all by themselves. When I initiated the high beam switch they stopped. All switches were already in the off position.
I put my original lights back in and operation was normal.
Can anyone tell me what happened and how to work around this issue?
I have a 1972 914-4 which I bought new in 1972.
[/quote
I will post a video because it is funny, but will wait until I find a fix.
The LEDs came from 914 Rubber and they may know how to fix the problem.

Check out this thread. Especially the last 2 pages.

LED Headlights: Turning on the fogs turns on the high beams, too!, New behavior, fogs worked normally until LED headlights installed.