Kentlexus

Found the problem why alternator only putting out 11.5 volts. At first, the alternator would put out 14.5 volts when the engine was cold. After the engine warms up, the voltage slowly drops until it is 11.5. Tested the alternator on bench test and test O.K. Plenty of voltage. Checked the battery, and battery O.K. No drop while engine is not running. Checked all the wires from the alternator to the battery and to the computer and the engine instrument light. Everything was good, no grounding problems or faulty wires.

However, when I removed the belt to check all the pulleys, to power steering, idler arm, and engine, I found the problem. The harmonic balancer was loose. The bolt was not loose, but the rubber which holds the hub where the belt runs, was completely separated from the metal hub.

While the engine was cold, the rubber would hold and the belt would turn the alternator so that I would have a 14.0 to 14.5 volts. But, as the rubber warmed up, it would slip on the ring and hub of the balancer, since the glue had fatigue and separated, and the RPM of the belt would slow down and the voltage on the alternator would drop, because the belt was not turning as fast as the engine.

So what at first appeared to be an electrical issue, was actually a mechanic problem which created a electrical headache.

Hope this helps others with the same issue with low voltage or voltage drop with no apparent electrical problem.