The reason I ruled out the rectifier, there are no codes...and he doesn't have to re-key the truck. That points me to the traction pot. With a fleet of 30 RC3000's , with most over 20,000 hrs, I've only replaced (1) 1rec.....countless 4 recs, and about 15 pots with this same condition. Of course, assuming all the switches test good.
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