4 Wheel Drive/SUVs: 2001 GMC Jimmy 4x4 not working, metal shavings, vacuum lines

Question
I have a 2001 Jimmy where the 4x4 will not engage. I have replaced the vacuum actuator, cable, and cable housing swirch, as well as the dash selector switch. None of the indicator lights illuminate on the switch even after replacement, and there is definitelt no action from the transfer case or differential when any of the switches are depressed. Where to next?

Answer
Erik,

Change the fluid in the transfer case, and check for metal shavings, or any other indications of faulty components.

Install a new, or additional ground cable to the transfer case, as many times, a bad ground can cause a similar problem.

Make sure that you are getting voltage/power to the switch, as you may have a broken wire, or something as simple as a bad in-line fuse that you aren't aware of.  Then, check the vacuum lines going to the vacuum actuator for the proper amount of vacuum to make sure that they are functioning properly.

After doing this, you may have to go to a reputable transmission shop (preferably one that specializes in 4-wheel drives) and have them check it out.

Carl