Measure the voltage on the two small nuts on the back of the alternator. This has to be done when the engine is running. One will have full battery voltage. The clue is the other one. Normally you'll find around 11 volts there. If it's closer to 4 volts, the Engine Computer / voltage regulator is trying to make the alternator work harder. If you find 0 volts, which is doubtful, you either have an intermittent problem or the person who performed the load test had the wrong wires or not all of the wires in the amp probe.
To verify nothing else is draining the battery, fully charge it for a couple of hours at the slowest rate on the charger, then see if it is still charged up hours or a day later. If it loses its charge, there is either a drain or the battery is defective.
Monday, November 29th, 2010 AT 12:03 AM