Packard Forum Index » Pre-War (1899-1942)

This sounds like a regulator issue. But the system should be tested using something other than the dashboard gauge.
The regulator may be out of adjustment. If momentarily grounding the field wire on the generator with the motor at 2200 rpm pins the needle then it's a regulation problem.

The argument about where the belt rides leaves me skeptical. If the belt is riding higher proportionally on each pulley then I don't see why the rpm at the generator would change very much. 42:21 is the same ratio as 84:42.

Belt slipping may be a better explanation, but there should be some noise present.

As well, if the belt doesn't slide under the damper the motor mounts are probably sagging. Just jack the motor up using a thick plywood square with a cutout for the drain plug channel.

Got the belt installed ok and drove the car to the generator repair shop. He tweaked the regulator and the generator is putting out 7.1-7.2 volts, which is pretty much per specs. All is good, no more belt squeal/slipping issues.