Mystery wire on 66 C10 with delux heater and AC

[Metalaroundstone]

I have a mystery wire on that I am hoping someone can identify. The wire shown in the attachment was coming from the heater fuse in the fuse box to approximately where the fan switch is. However, the fan switch was connected to the brown wire from the ignition switch, through what looks like a make-shift resistor made of a thin peice of metal. It got very hot when the heater fan was on.

My thinking is this mystery wire should be the one that goes to the fan switch, but the white connector on the wire would need to be eliminated.

I was thinking of running a new brown wire directly from the heater fuse to the heater switch, which is what I think is suppose to happen. Or is this connector supposed to connect to another pre-heater switch resistor, or something else, that is missing from my wiring?

I would appreciate any guidance on this.
Thanks
RT

[par4tom]

It sounds like the previous owner picked up the "accessory" key position off of the back of the key as he was unable to find an accessory terminal at the fuse box. Unless there is something wrong with the fan motor, I do not see why you would need a resistor inline with the heater.

If you want the fan to only work when the key is on, find an "accessory" hot that will show 12v when the key is on at the fuse box. The heater fuse terminal should work. (Use a circuit tester to make sure) I would not recommend running it on a constant 12v hot.

Also, I'm not sure how much amperage that fan motor will draw, you may want to put about a 5 amp to 10 amp fuse should there be a problem with the fan motor itself. No more than 10 amps.

Tom

[Metalaroundstone]

I think I may have answered my own question about the mystery wire. I think it is supposed to go to the cigarette lighter. If that is true, I am thinking that I am good to go to wire in a brown wire from the fuse box heater terminal to the heater switch.

Seem reasonable?

Man, I don't think there were more than a dozen wires under my dash that were going to the right place!

And now my ammeter seems to have bitten the dust.

RT

[tincan1966]

The normal fan heater fuse should be 20 amp. The older fan motors do pull alot of amperage with the old style resistors.

[spudder]

GM vehicles used a brown wire for power to the the heater. The heater should have a dedicated fuse at the fuse block where the brown wire picks up it's power.
The wire you have pictured is for a cigarette lighter. Lighters of that era had a pin on the the receptacle that the wire end pushed onto. Lighters were powered form a "battery fused" source on the fuse block. This provided constant power to the lighter even when the ignition was off.