Got a 2001 peterbilt 379 with Cat 6nz.
The engine brakes just stopped working, in about a 30 minute time frame. Jakes were working perfectly fine then about 30 minutes later i turned the switch on to use them and nothing.
Cruise control and oil psi is good. Got no check engine light. No slack in the clutch. Completely stumped.
Tried checking if its a bad switch by jumping the plug with a small piece of wire.
Cant check solenoids or anything yet. Currently loaded and on the road
Anyone have an idea where to look ?