911SC rear wiring question

[Makoshark72]

Returning 911SC guy here...

Quick intro.. bought '79 911SC a few years ago, gave it to my son when he graduated college. He headed off to Law School with the 911. About a year ago he was rear-ended on right rear corner. Damage was the right, rear corner was pushed in and down, no engine damage, no suspension damage.

Insurance company totaled the car, but I bought it back and am finishing a "restore" of body and interior. No branded title in WA state if over 20 yrs old..

As a result of the collision, the right rear tail light was crushed, and in repairing the damage it was easier to simply cut all the wires going to that corner. Now that I am getting it all back together, I am trying to get everything all wired up properly.

The corner wiring harness has a round 6-prong "plug" at each corner, mostly the tail light wiring. There is an additional hot wire and ground wire on each side, for the license plate lights. The right side has connections for the oil tank level gauge.

QUESTION... I have an extra set of wires (one from the car harness, the other to ground harness) on the left side, and also on the right side. The wire on the RIGHT side is hot when the light switch is turned on. Not so on the left side. Also, I can't seem to get the oil tank gauge to work, no matter how I hook up the "extra" wires on that side???? The wires all seem to be original, but badly discolored and faded. Hard to tell what the original wire colors were, so the wiring diagram is not so much help.

All the tail lights, reverse lights, running lights, brake lights, and license plate lights work fine.. I just can't figure what the "extra" wires could be for????

Any ideas??

Thanks!!

[santagrant]

The one on the left side may be for a rear fog light. on the right, may have gone to an engine bay light that was never installed.

[Makoshark72]

I thought about a rear fog light, but to my knowledge it never had one. Was that an option in 79, or would the car have had one as standard equip?

As far as the engine light, the wire is only hot when the light switch is on, I would think an engine bay light would not be tied to the headlight switch...?

I also need to sort out the oil tank gauge wiring...

Thanks for the help!

[santagrant]

Porsche didn't discriminate between ROW and US cars when making wiring harnesses. Therefore there may be extra wires not used in your car. Rear fog lights were a single bright light that could be seen from a distance. If you saw two lights, you might think the driver was on the brakes. When I get home, I'll check my wiring diagram and see if anything pops out.
Grant

[santagrant]

Rear fog light was an option. The switch on the dash pulled out to activate the front fog lights and turned to the right to turn on the rear one. The wires came thru the six pin round connector in the left rear. In the factory manual under #9 Electrical System, 3.3, has installation instructions to add both front and rear fog lights to the car.

The engine bay light wiring gets power from the headlight switch going to fuse #4 in the fuse box suppose to come thru the same six pin round in the left rear (typo - right??) and comes out as a solid grey wire to a single connector near the regulator panel and then to the light. It has a switch on the light to turn it on or off. To test this - If you took fuse 4 out, there would be no power traveling to the rear if this scenario is correct.

Hope this helps.
G

[Makoshark72]

Thanks Grant, I'll take a look at it today,,, Rob