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Mysterios red wire 900 1993

posted by  ODGuru on  Sun Feb 15 05:03 CST 2009
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last visit: Sat Oct 4 18:52 CST 2014
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Not having a 900 series but with a bit of extrapolation from 200 experience:

I'd ask: With the lead connected, what is the battery voltage with and without the engine running? What is the voltage with the lead disconnected?

If the running voltage is about the same, you will eventually drain the battery with the wire disconnected and the auto would not run.

Since an alternator puts out an AC Voltage, and the battery uses/needs DC voltage, a method of converting AC to DC is required.

Since a diode only allows voltage through in one direction, put one in the path of AC voltage and only 1/2 of the sine wave created passes through to the battery. Add more diodes in a pattern (bridge rectifier) and the battery only sees DC voltage from the alternator.

Since there are more than one diodes in the regulator, I would suspect the drain is coming from a bad diode(s) in the regulator.

If one or more of these diodes are faulty, it would allow battery voltage back through the system to the alternator ground.

I'd change the voltage regulator.

Duane






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New Mysterios red wire [900][1993]
posted by  maine-volvo  on Sun Feb 15 03:34 CST 2009 >


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