I tried running a new wire from the red wire on the regulator to the battery and no difference

 

Doesn't sound like a problem of voltage going into the regulator but voltage making it back to the battery. Check the negative ground strap on the engine leading to the battery. Plus can't remember on this model but should have a frame to engine main ground strap also. The ones on the 500 had a habit of breaking. Just can't find one for the 600. Only think I can think of is a ground problem or a wiring short somewhere.