Ill be driving along with no set pattern in what im doing, and the check engine light turns on, the voltage drops from 14 to 12, and my car kinda stumbles if I try to accelerate... im getting 2 codes actually, a P0300 random multiple misfire, and P0622-Alternator field not switching properly.



So I just changed my cap and rotor, and the front bank Wires, cant get to the back bank cuz the auto shop has to wait for an intake manifold gasket to get here. I also replaced my battery. Napa checked my charging system and they said it was fine. I just re-did all my ground coming from teh battery and going to the body of the car, in fact I added a couple more because I didnt trust the ones from teh factory. I check all the connections going to the alternator and they seem ok. I dont know what wires to check or what to do, I really would prefer not paying a $85 diagnostic fee.



So what can I do? is there some wires I can check? Or do I just need to get the alternator swapped?