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Battery Light On

2K views 8 replies 6 participants last post by  breathingfiredragon 
#1 ·
Hi all,

Last Sunday my battery light came on and off intermittently and then eventually stayed on I drove it the entire week back and forth to work. I took it in to a local parts store and had the battery and alternator tested. Results came back all is good. So I did some testing with my Voltmeter, and this is what I come up with; I checked the Volts at my battery unhooked and I had 12.3 volts and 12.4 volts (2 batteries), hooked it up and had about the same 12.3 Volts. Started it up and waited 2 minutes and had 11.8 volts, waited 15 minutes and accelerated the rpms to 1500-2000 and no big difference about the same reading. My first conclusion was the Generator was not producing enough voltage (stupid assumption):dunno:, so I purchased another one and installed it to get the same results. So I started looking in my workshop manual on troubleshooting. I checked the negative draw and the positive draw and passed. so I checked the ohms between the circuit between the generator and the PCM and I couldn't get a resistance reading. I am wondering if I missed something to look at or should I take it to the dealer to Diagnose the issue. Has anybody experienced the same issues?

Any information would be greatly appreciated!

Thanks,

Aaron
 
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#9 ·
Hi all, as I was looking through my discussions I realized I didn't update this thread. I ended up buying a new alternator from Napa, and this was the problem. Also i'd have to say within 1 year I had to replace both my batteries with 2 new motorcraft. I had a bad alternator out of the box the first time I replaced it.
 
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