scott.475

Is there a way to do this, either my self or by taking it somewhere? I really do not want to have to put everything back together again to test it if I can avoid it at all. I am still trying to track down my battery drain problem and I wonder if it is in the alternator, maybe a problem with the grounding...

the_supernerd

I believe you can take it to a place like Autozone. They have a machine with an electric motor and a belt. They put the alternator in the machine and it spins while they test the output.

ewarnerusa

I was at a Napa recently to have it done on the work truck alternator (F250). For some reason, our model of alternator wasn't in their database so it couldn't be tested. But try a Napa

Flamedx4

Look in the yellow pages for an alternator repair shop. (Auto Electric shop or some such.) They can test it more accurately than the parts store, and if it's bad they can generally fix it, usually while you wait and for FAR less money than a replacement.

scott.475

Thanks for the suggestions guys, but I guess the problem is not in the alternator after all. I totally disconnected it, but am still finding amperage draw. It is coming from the 40amp "AM1" circuit somewhere, just gotta track it down. I did find that that where the white ignition wire and white power wire are spliced with the white alternator wire there is some corosion, but I do not know if that would lead to battery drain. I will pull the heater relay tomorrow and see if there is still some amperage draw.

This is really frustrating, I have totally unsheathed the wiring from the under hood fuse block to the alternator, hoping to find the cause. I have all of the harnesses under the dash disconnected, but still experiencing current draw. Maybe the heater relay is defective, though I opened it once already and it seemed to be in the open position. Who knows...

the_supernerd

Pull each fuse and then probe the connectors in the box with a multimeter set to get a DC voltage reading. When you find one, and you know it is not the stereo or something else that uses a small amount of electricity, then you know where to start searching. A test light will also work, but might not light up bright enough on a smaller draw.

scott.475

This is so frustrating. I thought a multimeter would be the best tool for doing this, but I keep blowing the fuses in it, both the .5amp and the 16amp. This morning I tried testing from the battery negative to the alternator ground strap to see whether there was current draw, which blew the big fuse. I guess a tester light is really best, which I don't have. Time to make a run to the store.

BTW, I pulled every fuse in the underhood fuse box, but still finding amp draw when I can keep my multimeter fuses good...