Jake Brake

Mine has three switches for the engine brake. One switch is simply an ON/OFF switch. This switch obviously activates the engine brake. The other switch, next to it is the high/low switch which regulates whether the brake controls all six cylinders or just three. The third switch is the floor pedal which also activates the engine brake. Normally, I leave the ON/OFF switch in the OFF position. This allows the engine to cruise when I let off the throttle. If necessary, I press the foot pedal which activates the brake. That said, it appears your ON/OFF switch may have failed. I would start with checking your fuse panel(s) first. One in the front compartment and another in the engine bay. Make sure all fuses and breakers are good. Use a meter. If they check ok, then remove the panel and check the wiring under the switches. Sometimes they simply come unhooked and other times they fail. Switches themselves will fail also. You should have Carling switches but they will have proprietary Monaco numbers on them. You'll have to call Monaco to get the corresponding Carling numbers if you want to replace them from someone other than Monaco. Northwest RV in Eugene carries them and they are pretty inexpensive thru them...Dennis