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dte
08-14-2012, 12:00 AM
The other day while I was driving my 88 All-trac I noticed that the battery as well as brake and taillight lights came on but only around 3K rpm. I know that typically when they come on its a charging issue. So i turned off my radio and drove home, with the radio off i could go up to about 4k rpm before they came on.
Today I tested the Alt at home with my multimeter and it tested 14V at idle with radio on, about 13V with radio and headlights and fog lights on and 12V with radio head/fog lights and Blower motor on. As I increased rpm so did the Volts up to 14V. I know that with everything on 12V is pretty low Right? But I was expecting when I was Revving it up to see the Alt cut out at some point, Causing the Lights on the dash to come one but it Didn't. Any ideas? Thanks

alltracman78
08-15-2012, 05:09 PM
The brushes may be starting to wear out.
Or the voltage regulator.

When electrical parts go bad they can work/not work/work for a while, it's not like a mechanical part that when it's broke it's broke.

dte
08-16-2012, 05:31 AM
Figured it out. Tonight while driving as i would reach 4k my head light got super bright, so i figure the voltage regulator has gone out so the alt is overcharging the battery. Thanks for your help Alltracman.

pingpong21
08-19-2012, 12:29 AM
when that happened to mine my alternator totally went out. and i replaced it and everything worked again. those lights went away too

Galcobar
08-19-2012, 12:45 AM
Figured it out. Tonight while driving as i would reach 4k my head light got super bright, so i figure the voltage regulator has gone out so the alt is overcharging the battery. Thanks for your help Alltracman.

You might find this useful: http://www.celicatech.com/forums/showthread.php?12646-Is-my-alternator-going-out