My 330 A/BP (serial # HJ191607) is acting up on me. No matter what setting I put it on; it runs at max amps no matter what position the Rheostat is in. I tested the rheostat and it does not fluctuate ohms of resistance when I move it. I'm 99.9% sure that is my problem, but wanted to see if there was anything else I should check before I spend the money. BTW, I found the Rheostat at a really good price ($53 to my door) here and it is the same miller part number: