checkmate1996

Hey_Allen

I removed the LEDs and put the incandescents back in to remove the added variable, but found out that I have no power to the lights.
Testing back from that point, I don't have power at the dimmer connection, which is jumpered since the whole cluster bottom cover is missing.
I tested further, at the CE panel, and the fuses and the connection that I think is correct are all powered.

I did see a few people mention the led light pipe replacement options, but the ones that I have seen available were blue, and I'm a bit conservative on gauge lighting.

jpitman2

Leds work if polarity is correct, dont if not. The problem Allen had was some LEDs in wedge form have the wires wrapped around BOTH sides of the wedge and these produce a short in our pod. The wrap arounds need to be cut off so there is only one lead on each side. See these:-
https://www.ebay.com.au/itm/4X-WHITE...frcectupt=true
jp 83 Euro S AT 57k

Shawn Stanford

Yeah, I got bitten by this. I figured it out and rerouted the wire so it wouldn't wrap under the base.

Hey_Allen

I ended up modifying the LEDs that I have, by taking my Dremel with a cutoff wheel and cutting a slit along the edges of the wedge base, allowing me to bend the leads into the slit instead of over the back of the wedge.
The problem was that it already had lost power to the gauge illumination after my first foray into LED lighting and shorting the sockets.
I switched back to incandescent bulbs to remove a variable while trying to figure out what I'd broken.

Majestic Moose

Check fuse 5 (16A) for power with ignition on accessory (fuse is powered through X-bus). If good, check at connector B8 (goes to potentiometer) and F3 (goes to cigar lighter).

If you have power here but not at the potentiometer then the short burnt through the wire

Hey_Allen

I'll check that again.
That said, I thought it was the adjacent track on the IX schematic, showing Fuse 11, connector B8, direct to the potentiometer?


I have to ask, has anyone ever done a color scan of any original schematics?
I've gone looking to buy the originals if I could find one, but I've only seen one or two show up for sale, and none for the early cars. Those that were available were insanely expensive, likely due to scarcity driving demand.
The reason I ask is that I've seen a couple of pictures of one of the early schematics open, and they had color, both for the busses along the top, as well as for each of the wires.
I like that the b/w version is available, but with the blurred stripe along the right, and the muddling in some of the "connects to" blocks, it's not the easiest to use at times.

Majestic Moose

This is what I have, with labels.

Hey_Allen

Crud, one of the differences between '78 and '79 diagrams that I hadn't caught.
The wire color codes are written on the '79 schematic, and I'd been working off of it since most of it is the same.

Thanks for pointing that out!

Majestic Moose

Anytime

Hey_Allen

After numerous delays due to foul weather, illness, and family obligations, I actually saw the Porsche tonight!
The weather was cold enough that I was mostly just at my shop to drop off the newly acquired interior trim parts (glove box door, and cluster and column bottom panels), as well as a few service parts from one of the vendors here.

I did decide to test fit the new short shifter that I tacked onto the last parts order, and after a bit of fiddling around and fighting with the lower pivot rod and the plastic bushings, got it assembled.
I did not fire up the car and try to shift through the gears while it was running, but it is much less sloppy than the original shifter was, even though the little bushings in the shift pivots were all intact and in relatively good shape.
The gears were all able to be found now, as opposed to the sloppy mess that I was feeling when trying to find anything with the stock shifter and bushings, previously.


Here's to hoping that the weather doesn't get too cold this weekend, and that I can get the chance to sort out the electrical issues.

Hey_Allen

So, troubleshooting the electrical gremlins is leading me to suspect that I have a fault in the CE panel.

With key on, I have power at terminal A3, but not at F8, nor at fuse 5.
When I eventually got aggravated and applied power to the fuse, the lights all started to function correctly, including the headlight motor.

Any suggestions for a likely cause?

checkmate1996

karl ruiter

I have issues in the CE panel of my '79 from time to time. The backside of the panel is wires, rather than a circuit board. The wires have crimped ends, and those crimps can get corrosion between the end and the wire. CE panel is pretty easy to remove, and if you know about where the trouble is, not too hard to narrow it down. Sometimes the fix is easy, other times less so.

Hey_Allen

I ended up not getting to the garage where I store my 928 on Sunday, due to another snowstorm. I'm not too worried about a couple of inches of the white stuff, but the drivers around here get even more stupid.
Hopefully I'll get to the garage tonight and see if I can find anything obvious. Since I don't have any power at fuse 5, but did have power at A-3, I'm planning to test from A-8 and trace the wiring in the panel from there.
I may go through the diagrams and try to make a list of the various fuses and systems connected to each of the power busses as well. It seems like being able to easily determine that there is a problem with systems A, B, and C, which are all connected together at point Y, might be useful.