[VetteVet]

Originally Posted by DuallyFlatbed

Ok, so im wired strait? NO! NO! NO!

Pink to "ign"------ YES

Purple to "St"------YES

Red to "bat"-------YES

The heavy brown wire, the alt field wire, and the warning lamp wires all go to the same terminal..."Acc"? ----NO, This terminal is hot with the key on. The brown wire is the hot feed to the fuse panel for the accessories and the alternator wire goes to the external voltage regulator . The brown or tan brake wire is a ground path for the brake light in the dash and if a malfunction occurs in the proportioning valve it will provide a ground path for any hot wire that is connected to it. IOW if it is connected to the ACC terminal and the prop valve grounds it. Guess what happens. Instant short to ground.
All the info that I gave above pertains to the factory stock wiring and not to some Mickey Mouse switch the PO put in.

And this Acc terminal is just a ground to complete the circuit? ----NO I explained that in the paragraph above. IN fact you should confirm that the ACC terminal is hot when the key is switched to on or ACC. The ground check is not capable with this switch. If you leave off the brake wire then you should be able to use it. But it won't function but like the factory switch.

Any guesses y a ground would burn up end to end? I thought it would need voltage to burn up.

The ground would not burn up unless it gets voltage, which is why you cannot connect it to the ACC on the key switch.
As soon as you turn on the key it becomes hot and is a potential short to ground.