ESOF 4X4

[LUCKY_LARUE60]

Been have a problem with my SOF 4X4, some times for no reason the 4X4 light on the dash will come on and then go off when I have it in 2HI. Then when I need 4X4 it will not work, the light will not come on and the T case will not engage into 4X4. At time setting still I will shift it and I can hear the T case shift into 4HI. Andybody shed some light on the problem.

Thanks, Jim

 

[OLDBULL8]

Had the same type problem with my 99. Was told that the windshield would leak on the drivers side and water could get into the control module. My light would come on (4HI) when driving in 2WD and it would sound like the whole drive shaft was breaking apart. I installed a switch in the shift motor wires, and then just turn it on when I needed to go into 4WD. A new GEM cost is $320 and $100 to program it. The module is located behind the kick panel on the drivers side. Haven't taken mine out yet to check it. Truck is about a year old to me. There is a self diagnostic test, Remove the 5 and 8 wire connectors from the module. Turn ignition to RUN. Activate the self test switch. Flashing lite indicates module is OK, Steady lite indicates module is shot. Don't remove the 8 wire pigtail harness for testing.

Haven't had any flashing lite on mine for several month's now. Maybe it got wet just before I bought the truck and has dried out now. Looks like the windshield had been worked on. Don't know.

 

[OLDBULL8]

More thought's on that. Don't start the motor, put ignition in run then switch to 4HI or 4LO, crawl under and try to turn the drive shaft by hand, if it won't turn then it has shifted into 4WD, if it turn's freely it has not shifted into 4WD. Then start the motor and see if the hub's have locked in, they lock in by vacuum. If the hub's didn't lockin, then you have a vacuum problem, broken/disconnected vacuum line or the O'rings are not sealing. If the drive shaft turned freely, then the transfer case has problems. You said you could hear the TC motor running. The light should turn on when all the way shifted to 4WD. One other thing, you may have a bad selector switch.

 

[LUCKY_LARUE60]

Thanks OLDBULL, I will check things out now I have a starting point.