What is the purpose of the two fields? Does it matter which wire is connected to which field connection on the alternator? I'm having a similar issue to big red with my 74 Duster (square back alternator) , no charge at the battery with a fairly new alternator. Even got it tested by an auto parts store recently and they said it was "doing it's job." From the testing I've done, I've used a multimeter putting the positive probe on the main post of the alternator and negative Probe on a ground, reads ~12.5 volts when running. I also replaced the VR, which helped nothing. So I'm stuck with the problem either being the alternator is actually bad, despite the test, or there is some bs wiring mishap somewhere obscure. I wouldn't be surprised by the latter, the wiring in this car has seen better days.