Marker Lights/ Tail Lights Inoperative

[orph]

Checking with the experts here, to see if I'm on the right path.
On my 1986 930, the right marker light and tail light do not work .
The turn signals do function.

In looking at the electrical schematics, looks like the turn signals and taillights are on separate circuits, so what I described above makes sense. The fuse looks good and in fact I switched fuses to make sure a fuse was not bad but I could just not see it. Going a step futher, I switched out bulbs to make sure it was not a fluke both were out.

This leads me to believe a break in the wiring somewhere. If so, might I assume I can check with a multimeter ? Any other ideas ?

Thanks !

[JimNB]

It sounds like a ground problem. You need to take apart the assembly and clean all the contacts and grounds with some sandpaper.

The actual housing for the bulbs acts as a ground, so be sure to sand down the "cylinder" that the bulb goes into.

Hope this helps.

Jim

[911X2C]

Originally posted by orph
Checking with the experts here, to see if I'm on the right path.
On my 1986 930, the right marker light and tail light do not work .
The turn signals do function.

In looking at the electrical schematics, looks like the turn signals and taillights are on separate circuits, so what I described above makes sense. The fuse looks good and in fact I switched fuses to make sure a fuse was not bad but I could just not see it. Going a step futher, I switched out bulbs to make sure it was not a fluke both were out.

This leads me to believe a break in the wiring somewhere. If so, might I assume I can check with a multimeter ? Any other ideas ?

Thanks !

Hmmmmmm........sounds very similar to a problem I encountered. The problem is with a bad diode. For 1986 only, Porsche used a diode in the wiring for the right side parking lights.

It is in the wiring right under the dash. On the back of the light switch follow the grey wire and you will find this rectangular block inline with the wire. Kind of like a fuse holder but, it rectangular, the diode is inside the holder. I can't remember the Porsche part number right off hand, but I checked one time and it was like $18.00 from a dealer for the diode. Being the cheap bastard I am, I just went to a electronics store and bought a 4N1004 diode, worked like a charm. If your in a pinch, it will work without a diode, but I'm sure Porsche must had some reason why the diode is there. I've checked The left side parking light circuit does not have the diode.


Lee

[orph]

Lee-thanks for the info !

I got under the dash last night and darned if I can find a diode holder within a gray wire. I did find a rectangular type connector about 2" long, and opaque in color. It was however in a white/red stripe wire. Guess I need to dig deeper !

[911X2C]

You did find the right wire.......my mistake sorry. Yes the holder for the diode is opaque. In side, you will see a black rectangular object, that is the diode. The the opaque plastic object is the holder for the diode and can be removed. All you have to do is disconnect from the connectors from each end. Then to verify the diode is bad, connect the two wires together without the diode, then see if the right side marker/tail lights work.

Let me know how it works out.


Lee

[orph]

LEE:

You're my hero ! Did exactly what you instructed and worked perfectly.

Might I assume you just pulled the diode out of the holder, and replaced with the one you got from the electronics store ? Same identical size and thus fit ?

Again, thanks a million !

[911X2C]

Glad it work for you. No the diode I got from the electronics store is not the same size or fit.

This is what I did. I got two connectors that the connectors on the wires would plug into. Then I cut the leads on the to be installed diode so that with the connectors soldered or crimped on at each end of the leads, the total length is the same as the bad diode. I didn't use the opaque plastic holder. I just used some heat shrink tubing.

I figure if I ever see that Porsche diode for a resonable price, I will pick it up but, in the mean time, the replacement I'm using works just as well. Good luck!!

Lee

[orph]

UPDATE !

LEE: got the Doide from Pelican Parts an hour ago. Installed and everything is working just great !

Thanks again for your expertise !

[911X2C]

Originally posted by orph
UPDATE !

LEE: got the Doide from Pelican Parts an hour ago. Installed and everything is working just great !

Thanks again for your expertise !

Which diode did you get? The diode with the Porsche part number? How much was it?


Thanks

[orph]

LEE:

Part number is : 911 617 108 00

Pelican Parts price was : $16.50

Thanks again !