saberry0530

Just purchased a '07 A6 3.2 Quattro. Test drove great for the 15 minutes we drove it. First day on way into work (37miles) , EPC light comes on, ABS light comes on CEL shines and the battery indicator on the MMI shows 10%. car after 17 miles. It then stumbles and dies at the next light. push it into a parking lot. start checking things like battery voltage, fuses, grounds connections etc etc etc. nothing seems amiss. Battery voltage is at 12.87V which is good, but the OBDII software says the battery voltage AT the ECM is 9.8 when you try to start it, all you get is "click click click", like you would when that old Chevy battery was low. Put a jump pack on it, no change. played around about 15 minutes more and tried to start it again Started right up! Battery voltage at ECM is now 13.75V according to software, and the battery indicator on the MMI is slowly going up to 100% as I drive. Checked the ECM power relay, it is good, all the ECM power connections and fuses look good, voltage being output by alternator is 14.6VDC. Had battery tested under load , its at 93% rated capacity. Anyone got a direction to point me?? Alternator, bad ground, adaptive lighting current draw, not the correct phase of the moon?????? Thanks for any replies.