Alternator Not Charging

[Maxie Allen]

I installed a Delco Remy 3 wire alternator on my tractor about 1 year ago according to wiring diagrams I got off of the archives. My tractor runs fine with the aternator but I have had trouble keeping my battery charged. I tested the alternator with a load tester and an analog meter and my output only reads 13 volts at idle and 13.4 volts at full trottle. I had a man look at it and he said that my pulley was to large (I mounted the 5/8 in generator pulley on it) and that I needed a smaller pulley. Before I go out and purchase a new alternator could someone give me some suggestions/ recommendations who has had some experience with this. Thanks.

 

[Bob]

Make SURE the belt is TIGHT, and not "bottoming" in the crankshaft or alternator pulley.

Even if the pulley is a bit too big, that will only affect alternator output at idle, and the alternator should charge well at 1/2 or 3/4 engine speed. CERTAINLY enough to keep the battery in an "N" charged!

If the belt and pulleys check out OK, then run the tractor @ 3/4 throttle for a bit, then check the voltage at the alternator's large output terminal, and at the #1 and #2 terminal, and post back with the results.

 

[Dunk]

My pulley (the one off the genny) is too large too, mine is a 6 volt, positive ground, that I had special made for my prize possession (ok, so I am exeradiating a bit) mine is a one wire, Chevy alternator... I rev it up when I start out, and my battery is always charged up.