Hi,
There is no ground wire on the starter. You should have two wires. Once (larger in diameter) runs from the battery direct to the starter and should have 12v all the time. The other is smaller in diameter and should only have 12v when the key is in the start position. As far as ground, it is done by the engine block when the starter is bolted on.
I attached two pics below for you to see the wiring to the starter system. I overlapped them so you could follow easier.
Do me a favor. If you follow the negative battery terminal from the battery, it will go to the engine block. Unbolt it from the engine block, clean and inspect it. Make sure where it mounts on the engine is also clean.
Let me know if that helps.
Joe
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Saturday, April 25th, 2020 AT 11:01 PM