David M

After replacing the pulley on the alt. to cure belt squeal the volt gage pegs out at 18 volts above 1500 engine rpm. Pulled the alternator and replaced the voltage regulator and it did not cure the problem. The car is an '84 Z28 H.O. with a 94 amp alternator, and is a 1 year old A/C Delco reman unit. The alternator functioned perfectly before the pulley was replaced. Any ideas?

Stuart Moss

Is it a CS130 alternator? If so, there is a moulded connector on the rear/side with (normally) two wires going into it. The thicker of the two is the voltage sense wire that should be connected to the battery positive terminal. On my '91, it goes to the starter solenoid and then to the battery positive terminal via the 4 gauge wire.

Remove this connector (engine can be "off") and see if you have +12 on this wire. Are the connections, at both ends, of this wire good and clean?

The voltage regulator will use the voltage from this wire so it knows how much voltage to put out. If this wire is not connected, it'll be saying "I don't see enough voltage, I must produce more".

FYI, newer alternators are designed to shut the regulator/alternator down when no voltage is present on this wire (something the engineer's shoud have done from the start...).

Just an thought/guess.