Two days ago the lights go dim, headlights, instruments lights, check engine light comes on, but I make it to work. I can't take the vehicle to get anything tested, but I am able to get an alternator and manage to get it swapped out. It seems to work, but on the way home the next day, the check engine light comes on again.
So I take it to the local auto parts store where they test the old alternator (bad) and the new one on the jeep (also bad). So I buy a second alternator, go home and take the new alternator off, but before I put the second new one on, I decide to take it back to the auto parts store and test it again off the vehicle.
It now tests good.
I checked all the fuses, fuseable links, checked the positive and negative voltage drops, and checked the voltage across the fields which reads 2.17 volts but all indications say should read ~5 volts.
This tech bulletin which comes with the alternator: Online Technical Support Center
explains the circuit, however there is no indication on the alternator
as to which contact is field 1 and which is field 2, (and the picture looks nothing like the back of the alternator.)
The voltage varies between ~10 and ~16+ when running but the engine quits when I disconnect the battery.
With the ignition on, there is no voltage to either contact (which to me there should be to one, and that would tell me which is field 1.)
From what I can find on the net the voltage is regulated by the ECM according to this thread: http://www.wranglerforum.com/f8/volt...ion-28605.html
So at this point, is there anything I can do to actually test the ECM other than to buy one for $200 and try it?
Also, flashing codes:
12 - battery disconnect within last 50 key cycles
33 - A/C clutch relay (vehicle does not and has never had A/C and there is no A/C relay present in the fuse box)
41 - Alternator field
46 - Battery under volt (doh)
Thanks greatly for any relevant advice or directions you can give me.