1994 Mitsubishi Montero alternator troubles



I have replaced 3 alternators in a row and the “experts” keep saying they’re bad. The latest one charges the battery but can’t keep up with the A/C. Also, as I increase RPM’s the charge voltage drops slowly. What are we all missing??? ( Battery is new )


If there is an external voltage regulator in the system then that and the wiring from it needs to be checked for a problem.

The problem could be making the replacement alternator to put out a full charging output and that would cause a good one to go bad pretty quickly. To track down the trouble all the connections to the alternator need to be checked to make sure there isn’t something wrong there. The main alternator output lead and grounding between the battery and frame/engine need to be checked.


You might clarify the exact symptoms and is it known for a 100% fact all of these alternators were bad? Bad out of the box or allegedly bad after being run for a while?
What charge voltage are you showing? With the A/C on the voltage WILL drop.

What voltage is being shown at the battery terminals? The little red dashboard indicator light working?

Pardon the questions but not enough info is given to get real specific.