1990 turbo Eclipse with charging issues

1990 mitsubishi eclipse turbo 193,000, the car won't charge I have 3 alt. That test good on the, bench 2 won't work in the car, replaced battery, all connections cleaned and tight replaced all fuses, relays, light circuit functioning properly, resistances on wires appear to be ok, third alt worked for 300 miles after I had these problems but went back to same condition, any clue, could a bad ecu affect this? These cars are known for caps leaking in the ecu's. Thanx in advance