2001 Mustang 4.6 Electrical question

Recently the check battery light has been coming on at different times throughout the day. In the morning at startup, on the freeway, or idling at a stop light. I checked the original Ford battery, and the glass "eye" was red. This led me to believe the battery was bad. I replaced it with a yellow top Optima, but the check battery light still lights up. I too the car to Advanced Auto parts, Auto Zone, and Pep Boys to see if they could find the cause. Their machine couldn't find anything wrong. At idle the alternator was putting out 13.2-13.5 volts, and 20 amps. I have Steeda underdrive pulleys, but the techs said this was still an acceptable output. I have checked the cables, grounds, and alternator connections. All are clean and tight. I don't know what else to check. Anyone ever have this problem. Any help is appreciated.

Reply to
Fernando
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Ford states that the glass eye is only (I'm searching for a word here) believable for a short time from predelivery.... the little coloured balls can gum up giving a false reading.

I don't see a diode check if your diagnosis, but I do see an alternator that could be turning too slow.... the numbers posted appear to be for a no load test (and I'm sure your car takes more than 20 amps at idle to run).. This car repir stuff is simple, but not so simple we can avoid thinking.....

Reply to
Jim Warman

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