Four unidentifiable wires 1976 912E

[jlaudin]

I am posting on this forum, since the wiring should be the same for the wires I am trying to identify.
All of the wires are located under the driver’s front hood support strut. They mostly seem to be single wires coming out of a larger harness intentially.

First is a Black/Green/White wire (first photo) with the colours running lengthwise along the wire, rather than in a spiral around the wire. My wiring diagram indicates it has something to do with the flasher module and indeed tracing it back it forks after a larger harness exits the flasher. Can’t figure out what it should attach to, maybe to one of the gauges?

Next is a pair of wires, (last photo) I have seen elsewhere that these may be factory extras. On the solid brown ground, it originates from a plastic connector, where the other side of the plastic connector (shown being held in photo two) is brown with a white stripe, the other wire is solid green. Neither attached to anything.

Next I have a fairly heavy solid black wire (photo three) that splits from one of two “mound like” covers in front of the flasher harness. Not attached to anything

Lastly is a clear plastic junction connector (female female) (not shown) with a thin solid yellow wire, it is coming from a loom that has a thicker solid yellow wire. This is hard to get to, but it is just behind the tachometer. One end is not attached to anything.

Please see attached photos.

[gerakroo]

I think the black-white-green wire needs to be connected to your handbrake warning light. the solid black wire is most likely not original. I have no idea about the green and brown wire,but if there also was a black one, they most likely would be for the fuel meter.

[jlaudin]

Thank you sir!

[Jonny042]

Originally Posted by gerakroo

I think the black-white-green wire needs to be connected to your handbrake warning light. the solid black wire is most likely not original. I have no idea about the green and brown wire,but if there also was a black one, they most likely would be for the fuel meter.

Green is for the fuel gauge, and maybe in 1976 there was no low fuel warning light, thus no black wire?

[ossiblue]

The yellow wire, that is not shown, is in the location for the wire to the starter motor that originates at the ignition switch. If you disconnect that wire at the connector, the starter will not engage when the key is turned, if I am correct.

[jlaudin]

Thank you to all, there is a low fuel light in the 912E and it is functioning in my car. The black may be aftermarket, as I did disconnect an aftermarket alarm system. The black wire may be a remnant. I think I must remove the footwell blower motor in order to get a better look and access to make it right.

[jlaudin]

I have made some progress on identifying these wires (note below) but am still struggling with the black green and white wire. I have located a 912E specific wiring diagram, which indicates that the wire in question connects through a cable connector at “49a” which is consistent with 911 wiring of the same era. See photo attached. If so, it is a wire that comes out of the flasher relay and goes to the blinker wand switching. What doesn’t make sense to me is that the conventional Porsche scheme has junctions through a single cable connector unshielded at the female terminal end. My wire is shielded as is more typical a a wire terminating at an exposed female connector.
Gerako suggested it was a handbrake warning light, but that is working.
So I still could use help identifying this wire.
The yellow disconnected connector is disconnected by the factory. Looks like a spare if someone wanted to wire an accessory that would only work with the ignition switch on.
The green and brown also seem to be vestigial fuel level sender wiring not used in the 912E but maybe in a 911 as my low fuel warning light also works.

[timmy2]

Green/black/white wire:
For 1975 it is there in the schematic and makes the handbrake warning light flash. (See pic)
In 76 it was deleted in the schematics, but the factory likely used the same relay base wired up for the ‘75 and earlier . (Out of the parts bins)
Just tape it and forget it...

1975 schematic showing a second single wire from 49a of J1 relay to the parking brake lamp.:

[jlaudin]

Wow! That’s one I would never have figured out on my own. Thanks! What a red herring!

[timmy2]

Building new harnesses for many different years has forced me to have to deduce a lot of what was originally done at the factory when they made them.
There are a lot of similar “WTF’s” for many years...

[jlaudin]

I appreciate your work and willingness to reply on the forums. I am in the tail end of restoring a low miles (64,000) 1976 913E And trying to make everything “right”. I wish I had known about these anomaly’s before I disassembled all the blower fan components just to have a better look at what was behind the curtain. “Ignore the man behind the curtain” Wizard of Oz, 1939!

[jlaudin]

[timmy2]

Originally Posted by jlaudin