electrical and ignition Corroded Alt/reg D- Wire

[worzella]

I am cleaning and re-taping all of my wiring looms on my '75 and all was going well until I unwrapped the big bundle that includes the alternator to voltage regulator wires. This is the bundle that drops down from the alternator/starter and then across over to the inside fender wall up to voltage regulator. 

 

Anyway, all the wires were in great shape except for the D- lead from the alternator to the voltage regulator. 

It literally crumbled in my hands... the wire covering was split and falling away and the wire itself was brittle as hell.

 

The wire condition got a bit better within about 5 inches of the alternator plug (D-, DF and D+) but on the voltage regulator side I noticed a wire splice just before the voltage regulator connector. 

 

So something must have been going on with the previous owner(s) and a patch was made at one point.

 

Thanks

 

[allbim]

That's a ground wire and is not used to carry any high current. Simply replace it with #14 wire. The original color was brown, as are all other ground wires on that car. Make sure that you also have another short piece of fat wire going from the alternator housing to the engine block. 

Edited December 15, 2013 by allbim

[Hans]

Which may explain why it fried. If main ground is flakey, other grounds pick up the load. Best to check block to ground straps for clean connections.