Please confirm alternator diagnosis
Thread Starter
Racer
Joined: Feb 2000
Posts: 267
Likes: 0
From: Kelowna, B.C. Canada
Please confirm alternator diagnosis
I have had a recent battery drain.
Removed fuses – drain remained
Disconnect red wire from alternator – drain eliminated
Rebuild my alternator, new voltage regulator brushes etc.
Reinstall alternator – drain reappears – much less 2.5amps
Disconnect alternator – drain eliminated.
Test for continuity from car ground to red wire at alternator – none
Test for continuity at alternator red post to ground – none
My only guess is the windings are bad on my alternator. Any others things I am missing?
Removed fuses – drain remained
Disconnect red wire from alternator – drain eliminated
Rebuild my alternator, new voltage regulator brushes etc.
Reinstall alternator – drain reappears – much less 2.5amps
Disconnect alternator – drain eliminated.
Test for continuity from car ground to red wire at alternator – none
Test for continuity at alternator red post to ground – none
My only guess is the windings are bad on my alternator. Any others things I am missing?
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Instructor
Joined: Apr 2005
Posts: 101
Likes: 0
From: webster ny
The bridge rectifier makes sense as the problem (diodes) as they take the AC sinusoidal voltage (created by the alternator windings) and rectify one half of the sinewave, + DC Voltage out.
This output sill has to be regulated to maintain 14 V approximately by the voltage regulator.
The bridge rectifier diodes could become leaky over time, and allow current from the battery to flow to ground thruogh the diodes. A good diode will not conduct current in this direction due to the polarity. (+ battery/-cathode on diode)
Hef
This output sill has to be regulated to maintain 14 V approximately by the voltage regulator.
The bridge rectifier diodes could become leaky over time, and allow current from the battery to flow to ground thruogh the diodes. A good diode will not conduct current in this direction due to the polarity. (+ battery/-cathode on diode)
Hef
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