Testing it when you have a test engine isn't that difficult. I unhooked my test ammeter and hooked up the original gauge, then put a heater motor on the other side as a load. Since the test engine hasn't been ran for awhile, the battery was low enough for the Alternator to charge it. I could see the Charging Indication, and when I put the motor to it, I could see the immediate discharge indication. So now that I have done this, and seen for myself, I can confidently conclude..
Just look at the negative (Discharge) and positive (Charge) markings on the front of the gauge. They correlate to the wiring diagrams positive and negative.
When installing a wiring harness in a truck, the Starter/Battery connection goes to the CHARGE side of the meter.
Discharge/Minus on the gauge means Ammeter Negative in the wiring diagram. (Starter/Battery Connection)
Charge/Plus on the gauge means Ammeter Positive in the wiring diagram. (Alternator/fuel gauge/Load Connection)
Sometimes it really helps to have you guys commenting and keeping things on track. Thanks for your help.
