94 jimmy 4wd

gmc
jimmy

#1

hey, last time i couldn’t get out of 4low,

but resetting the puter did the trick, now however it has snowed again and it won’t go INTO 4wd…maybe the switch? or the relay thing under the kick panel? this was previously an arizona car, so the 4wd wasn’t hardly used out there…i’m in jersey…


#2

Try resetting the TCCM again.

Do you hear the Transfer case engage? If the transfer case is engaging and the 4Hi light is still blinking, check the Vacuum actuator that locks the front hubs. The actuator is under the battery pan, there is a linkage attached that locks the front axle. There is a vacuum switch that controls the actuator. This went bad on my 2000 Blazer. I pulled in/out lines of the switch and connected them, the front axles then engaged. I replaced the switch last year (~$70 dealer) and have had no further problems with 4wd. The switch is mounted on the middle of the firewall for the Autotrac system. I believe Controltrac mounts the switch on the transfer case.

Ed B.