I have a '94 Barth MH with 3116 cat and 5 speed MD3060 Allison. Shift pad does not activate with ignition or when engine is started. I have 3 relays in the electrical bay that deal with trans. When I jump 12v to the center relay with engine running it will trip and shift pad activates and MH drives as it should. When I shut it off then on again shift pad does not activate. All three relays bench test OK. 24 pin connector at trans is free of corrosion and arcing. Any ideas? Should shift pad normally cycle on with just ignition on run but motor not running? Or does engine have to be running to provide a "wake up call" to shift pad?