I have a 97 GMC Jimmy 4x4. found that the x4 is inop. First, some history. In the last two months I have replaced the heater, water pump, front crank seal, oil by pass housing seal. When I replaced the heater core, I failed to unplug a connector at the bottom steering column for the high beam switch located it the turn signal switch. I soldered a wire back in place but there is no high beam. when the turn signal is on the fuel gauge pulses with the flash. Now, I said all that for if need to know. I just found that the 4x will not kick in. All fused are good including the 4x4 fuse. It is electric operated. Panel on the dash with three buttons, 2 wheel, 4L, 4H. Neither light will come on when appropriate button is pushed. I removed the button assembly and checked that all bulbs are good. I checked and found that there is a pink wire to connector to button assembly that has battery voltage with the with the key on. I have checked all ground post that I can find. I have not been able so far to find a schematic for the 4x4 control. any advise, correct schematic and or ground locations would be greatly appreciated.
Recheck your repair work on the wiring. If you pulled on the wire harness, recheck all the wires! Then move on to diagnose your 4X4 problem. A scan tool can assist you in diagnosing the transfer case shift problem. Try tapping on the shift motor, if it engages, chances are you have a bad transfer case shift motor. Subscribe at www.ChiltonDIY.com for diagnostic trouble codes, repair procedures, specifications, technical service bulletins and recalls, maintenance intervals, and more. You can view, print, and save from the online information.