Finally got my new engine running with new parts (and I mean everything), and at the same time rewired front end with new headlight harness and all other wiring too, including new 4 gauge battery cables. Has Pa performance 3g alternator with AGM battery. MSD electonic ignition. Now I am trying to figure out why my voltage across the battery terminal, when running, fluctuates so much.
Please confirm that the voltage should not be swinging from 0 to 14.8 volts and everything in between when car is running. The reading on my volt meter across the battery terminals changes every second to some value between 0 and 14.8 v. Nothing constant. Also same result when testing at positive post on back of alt and negative battery terminal. Also same result throughout rpm range. Seems to get worse as things like electric fans start ramping up. When car is not running it is constant 13.1v.
What could cause this? Grounding? Bad alternator?