My problem has existed since I got my 73 Pantera. If I turn the key to ON and let it stay there for a while, the amp meter readings are normal at around 0. Turning on lights causes slight discharge reading. When I start the car, the reading stays at near 0 for a minute or two then jumps to about 50 amps +. It stays there all the while I am driving the car. When the electric fans come on, the reading goes up a few amps then drops back to about 50 when they go off. Turning on lights causes slight reading increases that drop off when the lights are turned off. The amp meter acts like 50 is the new 0.
I haven't had any problem with running or starting or battery discharge. The car acts normal. I replaced the battery and had the alternator tested. The car has had wiring changes in its history. The alternator is a one wire type and the output goes directly to the amp meter with the other side going to the battery + terminal. A wire goes from the battery + terminal to the starter relay. I haven't figured out how power gets to everything else in the car. There is a wire from the battery + terminal to a fuse block and relays that have been added in the front compartment behind the battery. I am guessing that power to things fed from the factory fuse block comes from wiring attached to the starter relay + wire side from the battery. I haven't yet been able to exactly track that.
Any ideas where to look for something that could cause the amp meter to stay at 0 for a minute or two after the engine starts, then jump to about 50 which acts like the new 0?
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