C3 alternator harness ground location?

[69427]

I'm making an extension harness for the alternator on my '69 due to its relocation onto the RH side. I'm making the usual extension of everything, but I'm just trying to make sure there isn't some odd item that would prevent me from also adding a short shunt wire onto the alternator bracket which is obviously bolted to the engine (a nice low impedance path). The original wires all disappear into the tape-wound harness, so it's not easy to trace. I'm still trying to locate my '69 service manual to see if there's any useful info in the electrical section.

Thanks,
Mike

 

[mrvette]

Alt ground IS engine/frame ground, sometimes I have seen really high current devices run to the alt directly, like fans to the stud on their own links, not through any of the car harness....

my fans were hooked to the alt directly for grounds some years ago, I got lazy and hooked to the frame, and they just as fine....

course engine is grounded by a nice ~6" battery cable to the frame under the pass side engine mount....

:flash:

 

[69427]

I got a reply on another forum indicating that this ground wire is to ground the headlights, etc, rather than being a part of the alternator circuit. This makes some sense, as I was wondering why Chevrolet "apparently" had such little faith in the alternator/bracket electrical conductivity that they went to the effort and expense to add an additional wire in the harness, and if so, where did they terminate that ground line.

Well, this should simplify life a little bit regarding the harness extension.

 

[010752]

The original ground in the harness goes to the lower front drivers side of the core support with a sheetmetal screw (poor) and then to the front header reinforcement bar (small threaded bolt, better) and then of course to the signals markers etc.

I always weld a 1/4-20 nut to the core support for a more positive contact and also run a #4 or 6 ground from the alternator case to the frame directly below to a drilled and tapped hole. IMHO the stock ground wires were a little on the light side.
I just consider the car frame as a big bus bar.

 

[mrvette]

The original ground in the harness goes to the lower front drivers side of the core support with a sheetmetal screw (poor) and then to the front header reinforcement bar (small threaded bolt, better) and then of course to the signals markers etc.

I always weld a 1/4-20 nut to the core support for a more positive contact and also run a #4 or 6 ground from the alternator case to the frame directly below to a drilled and tapped hole. IMHO the stock ground wires were a little on the light side.
I just consider the car frame as a big bus bar.

Yeh man, Greyhound.....


:bounce: