1997 ford f150 150,000 mi. i recently engaged 4 hi, the dash light came on, then went out and the tc motor would not disengage. i got under the truck with a hammer while my copilot flipped the dash switch. no luck. i removed the motor and manually turned the tc back to 2 wheel drive. i bought a new tc motor, installed it, and discovered i have no power to it. i have checked the fuses, all are good. i have read that there are relays, but im not sure how to check them. any thoughts and or advise would be great.

 

i have posted a ? , with my 97 expedition, looking for help too? no one has biten yet? at least we can manually disengage? my only outcome is to take it to the dealer .... $$$$$
any help would be appreciated, tom

 

i was able to get access to a scanner. came up with a P1820. which basically means that there is a problem with GEM (generic electronic modual). mine is located inside the dash, behind the radio, or so im told. i have not tried to enter yet. i will post more info as i go. good luck

 

P1820 should be an bad relay coil circuit for the clockwise rotation of the electric shift motor. The coil isn't being pulled in to send power to the shift motor.
I don't have a wiring diagram handy so I'm not sure exactly which fuse provides power to the shift motor relays. It's possible that the fuse blew during the 2hi-->4hi shift or maybe the clockwise shift relay is bad. Might be just a bad wire or flaky connection to that relay too.