m1super90

I may as well just change the regulator myself. Anyone know where I can get the part? (1997 Impreza 2.2L) Looking at the diagram for the Delco 10SI alternator, it shows a field wire and a sensing wire. This makes me wonder what the other blade is for on my unit. Looks like two pretty heavy gauge wires. I'm using a Legacy manual by Chilton (figure it's similar enough) and it diagrams out to that line going to the ignition coil. Any idea why they do this instead of running it from the battery?

Thanks Cougar. This morning... I turned the key to run w/o starting. The warning lamp was on. Using test leads I connected the field wire blade to the positive pole of the battery and broke the connection with the warming lamp. Upon cold start the alternator does not charge for one minute. After 3 minutes it wildly fluctuates between 14.7 and 15.8v. It makes sounds I've never heard from a healthy alternator before. After 5 minutes it quits charging again, for good. Turned the motor off and the key to run. Monitoring my test connection's voltage, I broke the connection and saw no increase in voltage. Indicating no current draw. I reconnected the charge warning lamp and it was not lit. With the field wire essentially connected to the alternator's output terminal via the battery, the feedback circuit must be fine. Also, after failure, it does not draw current through the field wire. Sounds like a problem internal to the alternator to me. What do you think?

I've read all about the Legacy alternator recall for late 90's years but I've seen nothing at all about '97 Impreza Outback alternator failures. This happened to me 2 years ago with exactly the same symptoms as reported on Legacy's. However, my mechanic, friends, nor online groups seem to ever mention my car having this failure. Well, it's happening again! Voltage drops to just over 12 and the charge and brake lights may come on. If they do, it's always simultaneously. Last time, the battery was drained dead via night time driving w/o the charge light ever coming on. Scary! Generally, starting cold results in good charge voltages. A few minutes of driving and the problems start: blower slows down, lights flicker, and charge and brake light sometimes comes on. My question is, has anyone seen the famed Legacy alternator failure in an Impreza? Also, this all happened after moving to Central Texas. Is it the heat and/or combined A/C loads that's doing it? I don't mind replacing the alternator but I want to be sure it's the problem. I somewhat suspect the feedback line (3rd wire). Any thoughts on that?