try the front driver-side storage compartment, which is typically where 'chassis/vehicle' fuses are located - I can imagine that there is a safety override for the Exhaust Brake function if the fuse is not providing continuity(a good fuse). Like an ignition override for your steps, which brings in the steps whenever you turn the key, the Exhaust Brake is a vital safety function for slowing down your rig, so not having the fuse continuity could create the 'non start' override for the engine.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada - Hiawassee, GA! (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )