I agree, that normally, running the alternator below peak output, shouldn't be an issue. However:-
-the output at lower rpm is still high (at least by comparison to the latest replacement).
-Unless someone is generously adding windings, giving me the wrong unit, etc..getting well over stock amperage must imply problems somewhere.

In terms of failure modes:-
#1 Died suddenly, battery light on.(10k)
#2 Flaky voltage regulation for about 1500m (lights dimmed/brighten with rpm. Then saw about 100m of "odd" voltage readings - jumps from 12V-16V. Then just 12V, but battery light did not come on (i.e something was coming out of the unit)
#3 Voltage went off-scale (>16V). Then pegged at 12V but battery light stayed off.
#4 Alive and well after 200m.........

All of which leads me to believe the regulator is getting fried, either directly or due to a faulty rectifier pack.

A few other considerations:-
1) Compass/themo LCD display goes blank at >16V (who knew..?)
2) Considered, tested , checked and discounted a bad battery connection. Running the unit open could cause the above behavior, but all connections were tight and showed no unexpected resistance.
3) Questionable battery? If there's an intermitant internal break, the alternator could powering into an open load. So far though, the battery seems happy and has given no signs of failure.
4) The reg/rectifier, being at the back of the unit sit very close to the header. I don't know if this is the case for other mitsu applications, but IMHO, this must mean the electronics get nicely heated.


The rebuilders could be reusing components or installing incorrect pattern parts. They could just be botching the rebuild. Point is check the paperwork (test results) before walking out of the store. I "trusted" the price of the unit and now know how to replace the alternator in my sleep.

Paul