Okay, so I need some major help..
When I had installed the MechMan alternator I realized my ride home from the mechanic yieled insane voltage variance so I called MechMan and spoke to Eric... He told me I should upgrade the wire as soon as I can since it needs to carry more amperage than the stock ... I went home and did the positive post to the positive terminal on the battery and then I did the alternator casing to negative terminal on the battery... Then I went ahead and did the adjustment to the avbm again since I wanted to make sure everything was charging right..
I called Mechman and spoke with Matt who told me I could use a mount hole that was on the casing but to sand off the coating which I did... so wiring was all done, I install a 300a fuse and good to go...
Now the issue is my voltage drops at idle to insane low numbers.... 12.6v and under... I called Mechman and they asked the resting voltage of my batteries and I couldn't give a definitive answer since I hadn't tested in a while... Matt stated that stock alternators have better voltage at idle rpm than the Mechmans since that is how they are manufactured.. and they kick in really at 700 rpm OK .... So I take it for what it is... On my way to work I was driving around and everything was great, voltage steady at 14.9-15.2v when above 1k on the dash... Once at a red light, my voltage began to drop to 12.2 and then 12.6 and then 12.0v ... I got worried and revved the engine to 1k to get the voltage back up .. at this point I turned off the music so I could see how that affected the voltage... At the next red light I experienced the same voltage drop to 12.0v then jump back to 12.6 ..
Again once I get about 1k the voltage is steady at 14.9v ... I am assuming my car is idling under 600 maybe even 400 since I'm guessing by looking at the needle...
What can I do to make sure it isn't the alternator?
I think I need to charge the batteries overnight ??.. I have a HC1800 under the hood, and a HC800 in the trunk....
attery resting voltages are : 12.76(front) and 12.72(rear) .... Is that okay???