Above is spot on. Also make sure all your harnesses are supported every 8” or more. It sounds like a disconnect plug (electrical) point is disconnecting or do you have enough grounds - engine to sheet metal sheet metal to batter and battery to engine.
If your mounts are isolating you may be finding ground thru the drive shaft. One bump and it disconnects the ground. Just spit balling I know you’re mad about the situation. Syleng1
