Starter won't ground when installed works fine on the bench but has bad ground when installed

I already tried cleaning the mating surface up buy it didn't help


Thanks

 

Just connect a thick ground wire from the starter to the chassis or the common ground on the engine to the chassis. But first check stock ground...take off ground wires and wire brush them and the grounding surface. Might have paint or something on them.

 

tranny to chasis is the starter ground.. make sure the starter makes good contact with tranny and that the tranny to chasis ground is clean and tight

btw, brushing works, but I would just sand down all the paint and even the starter connectors for a cleaner connection