I'm assuming you mean the bat reads 12.7 while the engine is running, not while off. If things were normal, the bat would read 12.7 when the engine is off, then jump to 13.5-14.5 with the engine running.
If the engine is running and it still reads 12.7 at the bat and 14.1 at alt, then your problem is in one of the cables/terminals/connectors. Probably on the positive side, but also check all grounds as well.
Use a voltmeter to check for any high resistance in a cable and all connectors for corrosion.
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Sunday, February 6th, 2011 AT 9:56 PM