Wire Identification

[Safetypup]

Hello,

I have been very slowly putting this 1961 T5 Roadster back into order. Today I did some fiddling with wires under the dash. While I was under there, I found a pair of "mystery wires" dangling.

One wire is black with a white stripe, and the other wire is brown I guess. They have bullet type (I think that's what you call them) connectors on the end.

The two wires are grouped/wrapped together pretty close to the end. There are a few loose inches, but then they bundle up together in what looks to be original wrap. That little 2-bundle goes up under the dash and joins the larger bunch of wires near the wiper motor. The master bundle they join also services the wiper wiring among other things.

The location is center in the middle of the dashboard. What are these for? I am guessing a radio. If I had one, it's long gone now. I looked at the 356 wiring diagram that is widely circulated on the internet for free and I only see 2-3 brown wires anywhere on the whole car. One brown stump looks like it goes to the radio, but I see no mention of a black/white wire. Could these be for two different things? The other brown wires go to things that don't make sense to me based on the location/length of the wires.

I plan to tape them up and zip tie them out of the way, but before I do that, I would love to know their function.

Thank you,
Brian

[ukinusa]

Check continuity of the brown to ground.
The Black with white tracer might be the to wiper switch - see diagram from 356 Electrics

[ukinusa]

pic inverted and cant fix

[Safetypup]

I should have put this in my first post...

My wipers appear to work correctly and I think I eyeballed all the connections a year ago when I was looking at those.

I kinda don't think these are wiper-related wires.

Is there anyone that has a drawing or diagram about how the factory wiring harness is laid out? You know, which bundles are routed where, what the connections are.

Thanks,
Brian

[ukinusa]

Ok see if either goes to ground by 12v and bulb through each in turn and see if they ground (bulb lights) - or a simple continuity tester ... then hunt !
Try with a ignition on - and after that try all the switches to see it any energize either ...
Could be a feed from Fuse #1 to coil ? least my color chart shows one simila
or from indicator switch to front indicator light
or from horn to horn relay
All else fails - do as you suggested and tape up

The whole schematic is available in a lovely color (laminated) chart from Greg Bryan ...
see http://forum.porsche356registry.org/...ic.php?t=35578

[roy mawbey]

I read this thread yesterday before Steve replied. I looked under dash of my 59 A as I knew there were two wires wrapped together not connected to anything. Been like that for the 51 years I have owned it. Both bullet connected ends one wire black with white stripe the other plain black. I have never worked out what they were for either. These wires on my RHD car are under the dash about 6" away from the centre. ( the bullet ends are well covered and looks factory to me)

There are more than few brown wires on my 356A though and that wire of yours that is not connected looks more orange to me?

I left mine as is, if all works well maybe just do the same or make those checks above.

Roy

[Safetypup]

Talked to my dad (previous owner since 1970). He said take a look at the ignition switch - maybe not everything is hooked up. He is the type of person that puts things back together with only what's absolutely required for it to run... handful of spare parts at the end is OK

So - On the ignition switch, the wiring diagram calls for a brown wire to be plugged into one of the "54" terminals on the ignition switch. My car has NO wire plugged into "54" (and the other couple of wires/colors all match up with the diagram and are present). So it's possible that my brown wire is actually the one that's supposed to be plugged into the ignition.

I did test both wires for continuity to ground and didn't find that.

If I say, "Ok that brown wire is most likely for the radio I don't have".... This leaves the black/white wire. I looked at the wiper motor wiring and that seems ok (the right colors are plugged in and the motor turns - not sure if the "park" position feature works or not). I'm a bit at a loss as to what else the black/white could be for. It's too short to go anywhere except wipers or something on the center area of the dash like the ignition switch or light switch.

I'll keep looking and update if I find out more. At this point, as far as I know, these two being unplugged aren't hurting anything as everything seems to work. (engine, lights, instruments, etc)

[roy mawbey]

I think my radio a Motorola was fitted when the car arrived at the AFN the London importer from the factory. They also fitted the Britax safety belts. Now the radio still original can be switched on without use of the ignition switch. I replaced this switch about a year ago and took a written note of the wire connection numbers. I will check that.
I also bought second hand in 1970 a used wiper assembly from a 356B T5. I looked yesterday and there are 4 wires coming from the motor one of them a black with white stripe. Also a brown wire.
I believe my 356A has a different make motor to the spare 356B one I have.

I think if everything works and they are covered those spare wires do no harm being left.

Roy

[Safetypup]

Made some discoveries.

I noticed that the color 356B wiring diagram (from pelican parts website I think) shows nothing on the #3 fuse "cold" (not facing the battery) side.

I noticed my car has a black/white wire there. Hmm. Sure enough, using a multimeter I was able to verify that my mysterious black/white wire is the same wire that goes to the #3 fuse position. My car doesn't even have a fuse installed there. So that's solved. I know where it goes - was possibly for some accessory or something - who knows.

My mystery brown wire is still a mystery - I couldn't find continuity to anything... not to any position on the fuse panel... not to ground. I do think it's likely it was supposed to be plugged into the ignition switch - but where the heck is the other end?

If you look at my first picture up top, you can see in the background is yet another wire that I didn't bring up in my original post. This one was hacked up (by my Dad I bet!) and had an extended piece spliced on with a funny non-porsche connector on the end. Did some digging on that one... the original part of the wire is red. That one has continuity to the #2 fuse position cold side of the fuse box. Checking the wiring diagram, there is indeed a red wire shown there going to a cigar lighter and a clock. My car has neither one of these. I have an oil pressure gauge there instead, but it was never hooked up. As you may have guessed, I also have no #2 fuse installed since it's not running anything. So that wire is the old cigar lighter wire just hacked up a bit. My dad confirmed that in the 70s there was a "junk non-blaupunkt" radio hooked up there he thinks that never worked anyway haha.

Just thought I would share. I'd still like to hear if anyone knows what type of function that black/white on the #3 fuse could have been.

Brian