Losing battery juice when sleeping.

May 18, 2007
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Aarhus
I just had this with one of my other cars.

It was three of the eight the diodes in the alternator (I don't know if this applies to a Supra) that had died. At first the alternator was still working and charging the batteri. Then after a few days it wouldn't charge anymore.

I was told if more of the diodes had shorted out the car could catch fire.
 

c_ronius

1jz 4Runner
Jan 2, 2007
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Tampa, FL
www.rsworld.com
Well the battery drain is fixed, but I think my alternator is cashed. All was fine for about the first 30 miles (12.4 - 15.3V running) then suddenly 11.8V on the gauge and 12.1 on the battery...no more charging. Drove it home and jumped in my other truck as I had to go. I looked at it only breifly, but it looks like the 120A alt fuse may be blown.

I'm thinking the alternator is bad, maybe something to do with my crossed wires? Maybe some burnt diodes or something. Definatly don't want any fires. Is there a way to test the diodes/regulator side of the alternator?

Any suggestions appreciated?
 

AaronsSupraMKIII

Supramania Contributor
Jul 27, 2007
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Athens, AL
My car is doing this also. Nice to know I am not the Lone Ranger. If I drive it everyday, it will usually start...but if its two days or more...no go. It is very frustrating.