Seems the alternator is charging but the charge is not getting to the battery.
You mentioned the alternator is producing 13.5 volts, did you test it at alternator or battery? Was the battery charging rate same as alternator main terminal?
If both are different, you have an open connection between battery and alternator. Check the wire connections from battery to starter and to alternator for open connections.
If alternator charging rate drops after driving, check for faulty cranshaft pulley.
Tuesday, April 7th, 2009 AT 11:22 PM