h011yw00d

Thanks, guys. Thats the bulb chart and advice I was looking for.

Now to go through them all again and make sure I have the right wattage bulbs. Sigh...

No third brake light in '85, Ed. Or at least not on mine.

PC-85-928S

Took a while on mine but eventually got it going with correct wattage bulbs

Hold On

Im not sure which lights you have indicating out. I spent numerous hrs yesterday fighting a tail light out warning when the lights all worked, then both the rear right and rear right marker went out. I traced the problem back up to the #3 pin on the lamp control box above the fuse panel. No 12V coming out that pin which feeds those lights. Removed box and found hairline crack in solder on that connection. Resoldered and all is good for now. No warning light when I turn on lights and all lights work.

h011yw00d

All the lights were slightly off wattage (9.4w instead of 10w, 24w instead of 21w) so I replaced them all per the Sylvania site and STILL the lamp warning is on.

I have Euro driving lights/fog lights, could those be setting off the tail lamp warning? I've read some say it's just the tail lights and markers that set off the warning and some say more lights are involved.

Also, Sean said that the side markers are 5w but the Sylvania site says 10w. Could they be wrong? Anybody else using 5w marker lights with no warning?

Hold On

My 83S has 10W on the tail lights and 5W on the side markers. I had the exact same problem with the warning coming on 5 seconds after I flipped on the lights. The lights worked fine. It turned out to be an intermitant connection(bad solder joint) on Pin #3 in the lamp control box. Everytime it would lose connection for a split second it would trigger the warning lamp. Everytime I looked at it out back, the lights were working.

Ed Scherer

Drew, I think Sean is correct and the Sylvania site is incorrect.

Perhaps I should have recommended the PET (i.e. Porsche) info. Sorry I didn't think of it sooner.

Check the parts list for your '83-'86 lights front and rear. That should be definitive. It shows those side marker bulbs as 5W.

Click either of these diagrams and you'll get the definitive answers.

NoVector

I think my PO used 10w and it melted the center of the lense, at least on the driver's side. IMHO, convert to LED using Ed's list in post #40 (may be a little different for your MY) https://rennlist.com/forums/928-foru...ich-one-3.html, disable the bulb control module and never look back. Well... if you do look back, it will be much brighter

h011yw00d

5W it is. I'll be darned. Thanks, Ed.

"Hold on" I'm hoping that since the warning comes on after enough time for the system to check the wattage and since it is consistent (always comes on with never a bulb out), that it isn't a control box issue. But after I go out right now and find some 5w bulbs, change out the markers for the 3rd time and that dadgum warning still comes on I'm cracking that baby open next.

Thanks, guys for all your help.

Alan

I belive rear & side markers are all 5W - they certainly are on S4's/GT/GTS

Where did this 10W spec come from? Also Sylvania?

Alan

Ed Scherer

Yup.

The frequently-recommended (including by me a number of times, too, although I think I'll stop doing it now ) Osram Sylvania app guide provides this for the side markers for the '85: 5008, R10W, 13.5 V, 10 W


Hmmm... I'm noticing it shows that same bulb for another place (e.g. "parking light") for my '90 that I don't believe is correct, either (isn't that supposed to be a P5W?).

It appears it's not quite trustworthy.

h011yw00d

I can only think they mean the position light and it's supposed to be 5w as well.

Switched out all the 10w side markers with 5w and no change.

It's gotta be the Euro fog lights. The US position light is a 12v 5w but there are no glove box size (like the position light in the Euro fog lights) bulbs that are 12v 5w. The one I have in there is 14v 3.36w.

You're right NoVector. It may be time for an led upgrade or at the very least a bulb control defeat. Sigh...

NoVector

Oh dude, you'd love the LEDs; especially the reverse and license plate lights--you can see so much better when backing up at night.

Alan

Foglights are not monitored.

Alan

h011yw00d

^^^ Aw, Jeez... Thanks, man. Back to the drawing board.

You guys rock! Thank you so much for everybody's advice and help.

dcrasta

5 Watt Side marker
5 Watt front 'parking' light
5 Watt Rear running lights (tails)
10 Watt brake and flashers
should work.
My tail light comes on and then goes out.
I do not have euro lights.
Clean your sockets and your connectors especially in the rear.