I know many have posted before(the same thing over and over), and I have taken the advice to change the overload protection relay, but still nothing. The tach turns on when the car is turned on then after a minute, it turns off. It does this all the time. I am currently stuck as to how to troubleshoot next.

I think the Hall effect sensor is fine because it gives a reading. It just shuts off then turns on again as if by a switch. Any ideas/help?