Question about 1984 Ford Ranger

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Im having a problem not getting enough voltage running through the truck put a brand new alternator on and when my truck attles my headlights go dim nd it shuts off

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  • adam martin
    adam martin Nov 11, 2014

    ive tried several things ive put a short circuit procted that has the letters i a s f i ran wire to s to postive and didnt help then ran i to postive termal still didnt help voltage



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Have a load test done on the battery to check for cell failure as the alternator may be putting all the current into a shorting battery. Check the output of the alternator as the regulator may be faulty. Alternators produce 14.5 volts at 2000 rpm and the current is set according to requirement. That is with 14.5 volts and full current draw the alternator is capable of producing the rated amps ( up to 120 amps) If you have extra power requirements ( driving lights --massive amplifier) the total current draw may be more than the rated amp of the alternator and so the battery will eventually run down and there will be insufficient power to run the ECM and it will stop.

Posted on Nov 11, 2014


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