Reply to "Amp Gauge waving like a beauty queen in a parade"

proceed at YOUR OWN risk!
I would first try a 0.1 F (1000uF), it needs to be rated above 20VDC. using a switch so I can put it in service and back out quickly if needed. it woulg go on either end of the wire going to the altenator field and the other end to ground.

the cap would act like a fast charge/discharge battery. so when the regulator steps the field current to max, the cap charge will cause it to ramp. when the regulatos steps to zero, the cap will cause the current to ramp down.

the time of the ramp depends on the cap size and the resistance of the circuit. from some online info, I think there is a 50 ohm resistor on the field wire to ground. thus with a 0.1F, the ramp from 0 to 80% will be 0.05 secs. this would reduce a charging cycle frequency of 3 htz and greater.

PS...
I found a good writeup on how to test the regulator.
http://www.fordification.com/tech/charging.htm
towards the bottom of the page there is instructions on disconnecting the regulator and using a jumper to apply full field. IF the amp meter is waving with the jumper (and the belt is not slipping) I would think the problem is bad connections in the wiring