Combines 1440 electrical problem

Take off the side panel under the window on the right side of the cab and take a hair dryer and blow it around all the wiring harnesses. I would guess that perhaps a ground or selenoid has poor connections. Also make sure all your fuses are not blown and are making contact. Good luck, wiring can be a bear in older machines.

Sounds like a faulty cab solenoid. It's on the rear wall of the cab after you remove the panel on right side. It might click when the key is turned on but still might not be switching power to the second large terminal. Sometimes if you switch the key on and off a few times it will operate properly. I know that's hard to do on a 14 series because that turns the engine off but do the check at the cab solenoid with just the key on before starting the engine.