4 Wheel Drive Not Working

[n1vek]

I have a 2001 GMC Jimmy with 4 wheel drive. I recently had work done on the radiator and I now can no longer engage 4 wheel Hi or Lo. The buttons just flash and it says in 2WD.

It may have something to do with a vacuum line being loose?

Any help? Thanks so much

 

[Molson02536]

I have a 2001 GMC Jimmy with 4 wheel drive. I recently had work done on the radiator and I now can no longer engage 4 wheel Hi or Lo. The buttons just flash and it says in 2WD.

It may have something to do with a vacuum line being loose?

Any help? Thanks so much

Read this post, http://gmcowners.com/gmc-forum/showthread.php?t=14184. But start with the simple since the radiator was worked on, inspect the vacuum line to your 4wd actuator located under your battery tray. Make sure that it's still connected to the actuator, if it's been disconnected. Remove the passenger side head light and you can gain access to the actuator where the vacuum line connects to.

If the vacuum line is connected and there is vacuum, inspect the actuator is self. It's common for the rubber diaphragm to rip and will not crate the vacuum needed in the actuator to pull on the cable that engages the front hub at the differential. http://i20.photobucket.com/albums/b240/Muslhed/Posi-Lok Install Pics/1FactoryVacuumActuator.jpg

Good luck and keep us posted.