1997 Nissan Maxima 6 cyl Two Wheel Drive Manual 186000 miles
My problem started as a battery that went dead when my car sat for 2 days. It went dead on its own - no lights left on etc. I traced the problem to the alternator pulling 0.5A all the time. I verified the drain was coming through the field supply by pulling the fuse for the field - when I did the drain went to 60 mA. I bought a new alternator and put it in. It charges when the engine is running (14.1V at idle), but the drain was still there. I took it back and got another new alternator. The drain is still there. I can hear a very slight humming (about 200 Hz) coming from the alternator when the field fuse is in. When I remove the fuse, the humming stops and the drain goes to 60 mA. If I remove the B+ wire from the lug bolt on the alternator the humming also stops. I'm stumped. I can't believe I have received 2 new alternators that were both bad. The problem is clearly current flowing through the field winding. I tried connecting a new ground from the alternator case to the battery - that didn't stop the drain or the humming. I'm stumped. Any ideas?
Sunday, May 17th, 2009 AT 5:50 PM