Final got the 76 Free Spirit out for its maiden voyage. New battery used during break-in needed charged the night before. Went by an Autozone and they hooked up the diagnostic box. Said starter was pulling right but Alt was bad. Went by another location that had one in stock and they bench tested mine first and said it was fine, so I put it back on. This makes me think it could be a grounding issue. When Autozone spins up an Alt, on a bench test, are they testing the ALT and the V Reg too? I have the ground from the firewall to the back of the head attached. The neg cable runs from the battery to the ALT bracket. Read in another post about another ground from trans to firewall? Any suggestions????
Hard to say. If the person running the test bench is not putting in the correct parameters, they will get incorrect readings. A bench check will not check the regulator if it is an external regulator, but "one wire/internal regulated alternators may be tested, again, if the test is done correctly. (Yes, I am not going to evangelize the "typical" auto parts clerk.) As to the grounding. Neg terminal to block (brackets with good clean bonding to the block is good), bonding wire from block (head) to firewall, and frame to body and frame to engine. Do you have a shop manual? It provides alternator, and regulator test procedures. If not, someone should have your year car manual and can help.
I actually ran a ground from the firewall to the engine to the frame as u did. There is also a ground from the battery to the fender mounting area
