Don't want to hijack this thread, but I don't think mine is working either.
I'm a noob to this. I have had the coach for about nine months now, and have made several local trips around Arizona. While the Allison is downshifting, I really don't think the exhaust brake is doing anything. Especially since the indicator light stopped illuminating shortly after the purchase.
How much of a deceleration feel should there be? Is the idiot light triggered by a switch on the PacBrake?
2004 Country Coach 40' Inspire Genoa - Cummins 350
1997 Lexus LX450 (aka Land Cruiser), Air Force One