Chonic Alternator Failure

I recall saying early-on to find the local rebuilder and get the parts from them and not any of the "Low Price" type chain stores. Nice to see others with the same experience and response. The problem is that now what he has for core is junk and they may not want it. I always keep the original anything and eat any core charge.

I was also thinking the 15.75VDC charge voltage was too high, but not being well versed in diagnosing charging systems I wasn't sure. 13.6VDC to 14.7VDC is what I'm used to seeing with deep cycle batteries.

At first what 67Dart said about voltage drop wasn't making any sense to me, but now I think that I see it. Measure the voltage between the alternator's case and the VR's case while the engine is running. It should be zero, as in 0.0 and not 0. something. If it is not zero then the difference in grounds will be skewing the VR to cause a higher alt output voltage than is correct.

FWIW with trunk mounted batteries I insist on a ground cable of the same size as the hot cable, and run it to a boss on the engine block. Over the years I've found that relying on the chassis from a high current ground isn't a good plan. Every weld in the chassis that the current has to cross is a resistor.