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Topic: Alternator putting out power, but battery not charging (Read 5 times) previous topic - next topic
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Alternator putting out power, but battery not charging
Yahoo Message Number: 138267
Dear Friends,

Thank you for your advice last week regarding purchasing the Alternator for our 'new' 1974 Lazy Daze.  Was able to install the correct 1-wire Alternator.  It is putting out 13v without problem (yes, wish it was a little higher, guess that's what I get for a refurb.)
 The bigger problem is that even though at the alternator it is 13v, there is no charge getting to the battery.
 Can I just wire the alternator straight to the battery, or should I try to trace the problem?  Does anyone have a wiring diagram for the 74 lazy daze?
 Also, we have the accessory battery out/disconnected (not using any accessories).  Could this be causing the problem? (ie, it needs a closed system with the accessory battery?)

Thanks Very Much! Andrew
Re: Alternator putting out power, but battery not charging
Reply #2 –
Yahoo Message Number: 138284
Quote
The bigger problem is that even though at the alternator it is 13v, there is no charge getting to the battery.
There are several ways the alternator output could be routed, but either should pass through a battery isolator - probably a dual-diode model in that vintage. You should be able to read the alternator voltage on one terminal, and slightly lower on the other two - if charging. If either output is an open circuit, you will read the same voltage as the alternator. If the isolator is bad, it will read much lower or zero.
 Typically, the battery positive cable runs directly to the starter solenoid, and the isolator output will connect to it at the solenoid. The isolator-solenoid run probably includes a fusible link. If you read alternator voltage at one end, battery voltage at the other, the link is burned out.

Steve
2004 FL
2013 Honda Fit
 
Re: Alternator putting out power, but battery not charging
Reply #3 –
Yahoo Message Number: 138302
Don't forget to check any auto reset circuit breakers -- we had one die of rust in our 85 that caused the same symptom..