Hi. I've looked through the postings on alternators but have just ended up confused. My 92 Legacy wagon has a 4 pin, round plug on the alternator. It has 4 wires attatched!. As it has been pronounced dead and I can not get one the same I was looking at replacing it with the later 2 pin one. Does anyone know exactly what the 4 wires do?. It runs perfectly without the alternator even connected so one wonders just what is needed...... Thanks....Michelle (New Zealand)

Thing is the original alternator has only 2 terminal. All alternators I am familiar with have an "I" and "S" terminal. As long as your wires that went to these 2 terminals also get attached to the I and S terminals on the new alternator, no problem.

Just find someone to rebuild it. It is a lot cheaper than new and is just as good