Later Model SI Alternator Grounded?

[DJ_Baar]

Do later model SI alternators require a braided ground wire connection? Old GM original on this old '67 C20 did use that, but had a separate voltage regulator. I now have a 12 SI installed and note that it has a ground lug, should I use it; I don't suspect it would hurt?

DJ

[Big Kev-O]

The alternator case is grounded through the bracket that is bolted to the engine block. You can test the connection with a multimeter by measuring the resistance (ohms) between the negative battery terminal and the alt. body. It should read 0.0 ohms or very close. That said you can never have too many or too large of a ground. I have my alternator grounded to the block with 4 gauge wire. My block is grounded to my chassis which is grounded to the battery. It does not have to be braided. It's always a good idea to upgrade/restore the ground wires in these old trucks. At least make sure all you connection points are clean shiny metal. Rust breaks electrical connections.

[68is4me]

I would ground It, its not going to hurt. The alt will also ground out through the brackets but now days most are painted or powder coated so they are a little tougher to get a ground through. I ran a wire from the alt to block, which also goes to the frame and battery.

[68is4me]

Ha, you must type faster then me Big kev.

[DJ_Baar]

Thank you Guys - I agree, never too many grounds, for complete circuits.

* Note the ground I have from engine to frame and shared connection with battery ground (2 AWG). Also changed all grounds on cab to frame when working this ground-up as I repaired the rust and getting 'er back together.