View Full Version : Alternator not charging under load

06-16-2014, 03:39 PM
I have a 93 prostar with the corvette LT 1. Alternator test fine, but only showing 9 to 10 volts on gauge. When you cut on an accessory (Hand Spot, blower) the gauge goes to 8 and alarm goes off. Anyone have any suggestions.

Bill Rosser

Table Rocker
06-16-2014, 04:14 PM
Get a multimeter and test the voltage at the post on the back of the alternator. Then test on the other end of the charging lead and so forth. You probably have some corrosion in the wiring somewhere. If you put one leg of your multimeter on the alternator charging post and the other lead on the other end of that wire (mine is orange) at the back of the engine, the amount on the multimeter is how much voltage is lost in that section.