I just got a new sleeper truck and can't get the bunk heater to go on unless the truck is running. Have been through the steps in the owners manual a few times with no luck. Any ideas on what I might be doing wrong?
Iirc, in my 07 780, the bunk heater won't start unless ALL OF a)the parking brake is set, b)the engine is off, AND the key is in the ignition. Maybe forgot something, too. Thought the darn thing was broken for the longest time. :^) Is yours different?