Please help Allisonman...I have a 95 Beaver Patriot with Cummins 8.3 and Allison MD3060 and I am having trouble with the exhaust brake. The switch on the dash lights when selected, and the transmission downshifts to 4th, but no retarder action. Just previously I had an Allison certified shop in the Battle Ground Area install a new TPS (cable was broken) and recalibrate the system but the problem persists. With the switch in the retard position if I disconnect the control wire at the exhaust brake relay and ground the terminal the retarder actuates. Where does the control wire get its ground? What do you suggest I try next? Oh BTW, the cruis control is also inop, the light on the switch does not come on when cruise is selected, are these problems related maybe a speed sensor on the trans? PS- A fellow pusher operator recommended you to me- was perfectly impressed with your operation.