I've got a 2001 2500 that I put a stock exhaust brake, from Dodge, on in 2010. It has never worked while using cruise control. I've always figured that it was because the throttle position senser never really goes to idle while using cruise control. That's just how it's always been, and I didn't care. I shut off cruise control when I get into the mountains anyway so that I can shift to whatever gear I need.
Recently, if I use cruise control at all and then shut it off, the exhaust brake won't work. I can cycle the switch all I want and it won't work. The only way to get the exhaust brake back is to shut the truck completely off. Then the brake works normally after re-start.
Anybody seen this one?