T case wont shift

[lkessler]

I have a '99 F250 with ESOF shift motor won't run in truck. checked fuses, checked wiring, swapped relays, checked dash switch in another truck, tested motor moves in both directions and shows up on dash 4x4 and low range with motor out. Reading other threads the only thing left it could be is the GEM? dont have any other electronic problems to support a bad GEM or can it only show one problem? Will have dealer check for codes ASAP, any other guesses??