964/965 Headlight Switch Question

[lucittm]

I noticed in our sponsor (Pelican) parts catalog there is a bulb listed for inside the dashboard switches. In my 1991 965 the fog-lamp switch and the rear-window-defrost switch both illuminate when the headlamps are on but not the headlamp switch.

Since this is a rotating switch, I pulled on the knob and it came off. There was a small bulb there to illuminate the knob, I think. The bulb is not listed in the 964 parts list but in the 993 parts list it shows 900-631-132-90 for a 1.2W bulb for the fog-lamps and rear-window-defogger switches.

The bulb is marked OS 12-15/30 and it tested good on the ohmmeter. Should I try a new bulb or it there some magic formula to make the bulb come on. Porsche used different switches because the fog-lamp and rear-window-defroster are pull-switches (how do those knobs come off???) Maybe Porsche never wired the bulb to come on in the headlamp switch?

Funny how you know your own car and never stop to think, "Is this the way it's supposed to work?" I could go to the dealership, but this forum is so much more fun.

Thanks,
Mark

[davisriley]

If I am not mistaken, I think that they did away with the lit up headlight switch very early on in production because at night when it was lit up, there was a reflection in the side window. I seem to recall a thread about it somewhere.

[stevepaa]

http://forums.rennlist.com/rennforums/showthread.php?t=269052&highlight=headlight+switch+light

[lucittm]

Thanks for the link above. Based on the Rennlist.com thread, the switches wired on Wednesday and Friday light up, but if your car was build on any other day it was not set up that way.

Hey, I learned from the Rennlist that there is a lamp behind the cigar lighter? I never knew that before. Those Germans are tricky...

I am looking for a copy of the electrical wiring for my 1991 965, when I find it I will post the answer to the list. Maybe I can wire the H/L switch to make it come on only on Wednesday and Friday. Or, at least when the door has been opened, at night, on a time delay to fade out 10 seconds after the car is started.

Thanks,
Mark

[lucittm]

Well, I received my 1991 Porsche Wiring Diagrams in the mail last week. The turbo model (sorry, I didn't check the others yet) shows the headlight switch with nothing connected to the hot side of the bulb. It would be quite easy to fashion a jumper from the terminal on the headlight switch to the common terminal that connects to all the other instrument and knob bulbs.

Does anyone have a section of wire that is .5mm and insulated with grey and a blue marker? Do I need a couple of connector pins? Maybe I should concentrate on how to remove the headlight switch from the dash. I have never done that one before.

Also, in the wiring diagrams, there are these square boxes (not rectangles, those are the coordinates). What are these boxes besides common connection points and what do the numbers inside the boxes mean? It almost looks like they are just numbered in order.

Thanks,
Mark