I have a 1997 f-150 with the electric shift four wheel drive. Recently after putting in four wheel hi or lo it doesnt want to come out of 4wd. Well the last time i put it in 4wd it would not come out at all no matter what i tried. I pulled the electric shift motor off and it does not turn when switching positions. I heard the GEM module is what tells the motor to turn. I was wondering how could I check to see if it was the module or the motor bad. Because the motor is $250. I also turned the shaft and put it in 2-lo manually and, the lights on the dash still says 4-hi. I talked to a mechanic and he said it could be the GEM module the fwd module under the dash or the motor. All too expensive for hit and miss. Any help would be greatly appreciated. Also where is these other modules and could I possibly change them myself because I really dont have the $$$ to pay someone.Thanks