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nissan
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Discussion Starter · #1 ·
A few weeks ago, the alternator in my TB42 GQ croaked it. After replacing it, everything seemed fine (good 14.5V charge), but the next day, the battery was completely flat. Charged it up, and connected an ammeter to it. It's drawing 2.5amps with the ignition off. If I disconnect the white spade connector from the alternator, the current draw drops down to a few milliamps (consistent with my clock and radio). Any idea where I can start on this issue?

Cheers
 

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Hi,

Is there any wiring the car didnt come with ? Check there first. Next step pull the fuses 1 at a time. When you find the fuse, see what it runs and then disconnect each thing 1 at a time. If you are losing around 30 watts it shouldnt be too hard to find. Is it a standard stereo ?

Regards B M
 

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Where did the replacement alternator come from ?

Was it second a hand or reco unit by any chance, sound like it could be faulty diodes in the alternator to me ;)
 

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Where did the replacement alternator come from ?

Was it second a hand or reco unit by any chance, sound like it could be faulty diodes in the alternator to me ;)

Thats what i was thinking
 

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Yeah that sounds very much like a faulty diode my alternator is doing exactly the same thing at the moment... sometimes with the faulty diode you can check to see if it is leaking AC current back to the battery by checking for AC current between the white plug and the battery.

The result of the diode failing will usually allow non-rectified power back out. (Sometimes, not all the time).

Rectified power being the AC power the alternator generates being converted into DC.
 

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Discussion Starter · #9 ·
Yeah that sounds very much like a faulty diode my alternator is doing exactly the same thing at the moment... sometimes with the faulty diode you can check to see if it is leaking AC current back to the battery by checking for AC current between the white plug and the battery.

The result of the diode failing will usually allow non-rectified power back out. (Sometimes, not all the time).

Rectified power being the AC power the alternator generates being converted into DC.
Thanks for the help.

Ended up returning it and buying a 100A unit from Patrolapart in Lilydale. As the previous owner of my car has nicely cut off the connector plug for me, I just need to work out which wire goes to which connector on the alternator, and I should be sweet.

Cheers!
 
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