Bill Ball

Well, my reliable 89 did something odd on the way home tonight, fortunately very close to home. The lights went out, flickering off and on, both high and low beams, both headlights. The driving lights still worked on high beam. That would be the saving grace if the headlights went out, but they kept going on and off.

There was no effect from jiggling the light switch or the ignition. It only happened while driving, seemingly related to the jostling of going down the road. So, I won't be able to tell if I have fixed it by doing anything in the driveway.

I saw no other electrical oddities while this was happening.

I did a search and found other headluight issues, but not this one.

Based on the description where should I look? I did replace the headlight combination relay a while back. I guess I should check that and at least make sure it is seated properly. What else?

heinrich

Bill that is Porsche Option 54 .... "Diskothekscheinwerfer"

heinrich

Imo000

Start with the relay, maybe as you said its loose of the contacts are a little corroded.


I lost all my light 2 years ago jsut as I was crossing the finish line at the local drag strip. This was around 10:30 (pitch black) and the fog&driving lights saved my butt. Ended up driving home (60 miles) only on those lights. They are barely enough to see but you have to pay full attention.

Bill Ball

Thanks, H'man. I'll just turn up the BeeGees and enjoy it.

GRTWHT

I have had the same problem but with only the left headlight. This too a while to iron out but in the end it was just a bad earth. In the wire to the chassis itself, not where it contacks the fram or in the headlight assembly itself..... in the wire.
The ground wire over time has corroded internally under the insulation and lost contact. Intermittent while driving almost drove me mad looking for the fault, but that was it. So I just ran another lead from the headlight to the frame at the front left with all the other ground points are. Fixed.
Regards,
Glenn '81 928

Mike Frye

Bill,

If you can get them to strobe fast enough, it will look like you're the only thing moving .

How about the plug by the jump post. I think that harness is the last place where you've got power for both lights (after that I think it would be an issue with just one light). If it were the relay/contacts in the passenger compartment I don't think it would be as susceptible to road bumps.

Maybe it got moisture/corrosion in it and it needs cleaning?

SharkSkin

Bill, check the grounds, also try tapping on the relay. Resist the urge to tap on it with a sledgehammer.

Bill Ball

Yes, the fact that it is both lights in unison is a key observation. I think the grounding is per lamp. I was going to review the wiring diagrams, but I'm so bad at it, I thought I'd let you guys do that!

SharkSkin

IIRC the relay is the last single circuit. After that the power splits through separate fuses.

Bill Ball

Thanks, Dave. I printed out the wiring diagrams and will try to decipher them. I'm hoping it is a minor glitch with the relay. None of the other headlamp functions are affected - the lights are going up and down normally, etc.

Bill Ball

I found the relay to have very clean contacts and it seemed to be seated. However, when I reinserted it, I noticed it had a tendency to tilt out with very little pressure, pulling the top spades at least partially out of the socket. So I wedged some foam under it to keep it in place. I need to snug up the female ends in the socket to hold the realy more securely. Hope that was the cause. Still studying the wiring diagrams...

ew928

Do the switches that activate the headlight when the pod flips up ever go bad?
Ever work itself loose so headlights gets down and bogeys.

Hope you don't end up driving behind some trigger happy shortfused angry driver or behind a pohleese cruiser at night.
Can a cruiser pull you over from in front?

Ernest (NYC) 2.5 months into H3 HID fogs and they're still running.

the flyin' scotsman

Bill............I had a similar issue last year ...........both headlight bulb sockets were burnt; replaced them and the bulbs; job done.

Alan

Bill,
Did you happen to try full beams when they were flickering? did they flicker the same way?

Most likely if its only the low beams is the relay or connections, if both Hi-Lo do the same flickering I'd say check the limit switch connections for the pod position (This feeds the relay for both modes - and on an S4 the pods will stay up if it fails - consuming power and warming up the motor no end)

Alan