Holy smoking dashboard wiring Batman

[Tdskip]

Hope the week is off to a good start for everyone, hoping to get some help here on why my gauge wiring just decided to start smoking like crazy.

The blue/yellow wiring that powers the gauges got hot enough that it started smoking. Looking the wiring diagram it appears that that color wiring powers all the gauges so somethign is shorting out that it is connected to.

I've read that a failed bulb socket might be be responsible for that? Other ideas?

Thanks in advance for any help/suggestions.

[gerakroo]

This wiring is not connected to a fuse and when you get a short it will start to burn. It would be best to disconnect the whole loop and see how bad the damage is first ! In any case add an inline fuse to it. (everyone should do it)

[julerb]

Gerald,

Would you care to expand a little on how you would fuse it? Maybe where the easiest place to access that wire? Possibly a kit that would look like the factory had done it? By the way the harness I put in my 356 was a very nice piece of work.
Thanks,

jule
Jule

[myflat6]

here is a link to where i purchased my inline fuse from. i installed this in both of my 911s. easy install and great peace of mind.

https://911bestinclass.com/products/...shboard-lights

[Tdskip]

Thanks for the discussion.

My car is a 1970 and it was the blue/yellow which started smoking, and I believe that is fused at #2 on the lower fuse block.

[Tdskip]

I did some testing with the multimeter and that circuit is definitely shorted to ground. All of the other wires are OK, and even when all the leads from the blue/yellow are disconnected that circuit is still grounded.

Wondering if I can run a temporary wire from the fuse box to the gauges one at a time to help determine if the gauges are OK and that short is somewhere in the wiring loom before it gets to the gauge terminals.

What do you all think about that approach?

[Jones]

I did some testing with the multimeter and that circuit is definitely shorted to ground. All of the other wires are OK, and even when all the leads from the blue/yellow are disconnected that circuit is still grounded.

Wondering if I can run a temporary wire from the fuse box to the gauges one at a time to help determine if the gauges are OK and that short is somewhere in the wiring loom before it gets to the gauge terminals.

What do you all think about that approach?

I was looking at the diagram for your car from this post: https://www.early911sregistry.org/fo...iagrams-in-PDF

It looks like the blue/yellow wire to the gauges is spliced into the red/black wire from the ignition switch that feeds fuse 7 ...so not a fused circuit.

I'm not a 911 expert, but I am an automotive electrical expert, and I would suggest tracking down the cause of your short first is the way to go. As that circuit feeds bulbs in the gauges, I would pull all of them and have a look.

I can offer some more diagnosis tips if you need them.

Good luck!

[gerakroo]

The blue-yellow lead comes from the molded ignition switch connector. There no fuse behind it. It would be best to remove the tape from your harness and see how bad the damage is. The wiring in the wiring harness is often mixed up and it is therefore very possible that other wires have also been burned/damaged because the blue-yellow wire was touching it. To measure you will need to disconnect the red (or sometimes red-black) wire connected to fuse 7, this wire is connected together with the blue-yellow one inside the ignition switch connector.

[gerakroo]

Gerald,

Would you care to expand a little on how you would fuse it? Maybe where the easiest place to access that wire? Possibly a kit that would look like the factory had done it? By the way the harness I put in my 356 was a very nice piece of work.
Thanks,

jule
Jule

I would cut it where it exits the main trunk harness and put an inline fuse in between. Good to hear you liked the 356 harness !

[Tdskip]

Here is the wiring that burnt.