Why is it that when guys ask members for help they can not supply more info to help the cause?
1. what gauge power wire and what length?
2. What size ground wire, gauge, and length?
3. Are you using a stock starter relay or after market? (I like the Ford ones.
4.what starter and when was maintenance done to it.
5. did you ever clean the surface where the starter bolts on.
6. Since you are grounding to the starter did you ever try going directly to the engine block.
7. Did you use a chassis ground too?