alternator wire

[wlevin]

To the alternator-savvy folks on the site-
This weekend I noticed that a wire on my Mando 55 amp alternator was fried. I think I must have done this at the beginning of the season when I shorted something while installing the alternator. At the time I could not find anything wrong, and the alternator worked fine all season, so I didn't worry about it. The picture shows the wire that I replaced this weekend. It goes from the positive output terminal to another post. I have not run the engine since replacing the wire. Can anyone tell me what the wire does, and whether I need it afterall? Also, what guage does the wire need to be?
Bill on Otter
T-34 C

[Don Moyer]

Bill,

I'm attaching the instructions that come with a Mando alternator. You'll have to rotate the photo in the instructions to align with your photo, but when you do, you'll see that the short wire from the output terminal to the nearby terminal is a sensing wire that the regulator uses to control alternator output. With this wire removed, I'm not sure how the alternator would have been able to work, but my guess is that since you have an external exciting wire, the regulator sensed the voltage in the DC system via that wire.

Don

[wlevin]

Don
Thanks for the information. I suppose it is possible that the alternator sensed the system as you guessed, or that it just kept charging all the time without lessening output, but nothing, including the batteries, seem to have been ruined. Better lucky than smart.
Bill on Otter
T-34 C