Problem With Charging System

[Mopar-Charger]

I'm having a problem with my charging system.

1. Tach needle fluctuates, while the car maintains RPMS (wiring is fine, all grounds are grounded)

2. While going over 2k RPMS the alternator A/C on the dash alternates between D and C equally. keeps going back and forth. when this happens, the lights dim, then come back. On going cylcle only over a certain RPM.

I'm thinking it's a problem with the alternator, I put in a new Voltage regulator, and still had the same problem and everything else has not been touched. Has anyone experienced this before? How should I go about diagnosing the problem?

Car still runs and drives perfectly fine. I just have those few problems.

 

[Jackpot50]

Check grounds again.
Put a multi meter on alternator and see what you get there.
Your can raise the RPM while watching it then have some one turn on lights

 

[Bruzilla]

I agree with Jackpot. When a lot of weird, unconnected, electrical issues pop up it's almost always a bad ground somewhere.

 

[mopar73dge]

its always bad grounds and bad hot connections, check voltage at the ballast resistor as stated in the shop manual.
that will tell you if the regulator is good, while car is running remove the positive cable off the battery, if the car still runs, the alt is good.