SWB Taillight Bulb 1968

[Simonjjb]

The 1968 specs for the rear Stop light bulb refer to a twin 25/3.2 Watt Bulb.

In a number of places this cross references to a Osram or Hella# 7528 which is a 21/5 Bulb. That would be ok except the problem is that the pins on this bulb are offset, whereas the fitting is not. This means the bulb doesn't fit properly.

I can find the N177382 Bulb which is a VW part and is 18/5. There is also a N0177372 Bulb which is also 18/5. What I can't see from the photos of these two bulbs is if these bulbs also have offset pins? What are others using?

[Jim Breazeale]

The 1968 specs for the rear Stop light bulb refer to a twin 25/3.2 Watt Bulb.

In a number of places this cross references to a Osram or Hella# 7528 which is a 21/5 Bulb. That would be ok except the problem is that the pins on this bulb are offset, whereas the fitting is not. This means the bulb doesn't fit properly.

I can find the N177382 Bulb which is a VW part and is 18/5. There is also a N0177372 Bulb which is also 18/5. What I can't see from the photos of these two bulbs is if these bulbs also have offset pins? What are others using?

You are trying to put a 2 pole bulb into a single pole fixture. There are 2 single pole fixtures and one 2 pole fixture.

[Simonjjb]

Yes, I initially thought I was that stupid as well. But if you look carefully it’s a 2 pole. See photos below. The first one is the one above and the second one is another one that works fine. The far right is the single one. You can also see that the one that works has the slots for the offset pins. The one I’m having trouble with doesn’t. Seems it like a hybrid.

[Jim Breazeale]

A dual element bulb will always have offset pins. That way, it can only be inserted on one direction. I have observed over the years that the dual element fixtures go bad much more often that the single ones. Someone must have tried to make a dual element fixture out of a single element fixture

[911Priest]

The far right is the single one

[Cliff]

https://www.stoddard.com/porsche-911...ght-bulbs.html
I bought some of the bulbs above, seem to work , so far. I also ran into the PO jamming a double pin bulb into a single..

[68911+1]

There was a simple jumper wire modification and a swap for a single plug for a double which added a "running light" function to increase visibility. AIRC, it added the running light, dual filament, to the brake light. It was documented in the Up-Fixin books many years ago and could be done to all 4 corners. Perhaps that was done. It was actually an excellent upgrade long before LED's.