My 4wd select switch stuck 4 wd will switch into low but will not go into auto or 2wd

SOURCE: 4 wheel drive wont swich back to 2 wheel drive

After reading some of the fixes here and on other forums,i bought a vacuum actuator and a transfer case switch.My mechanic came to fit these today,replaced the actuator and it didnt do anything.Turned out the old one was o.k..He couldnt find where the case switch went ,so he started tracing the vacuum pipes.
Guess what? he found not one ,but two broken pipes.he replaced/shortened these and hey presto,i now have 2,4 hi,4low and auto all working again.
It may be worth checking the vacumm pipes before buying other parts.
Just a thought...........

SOURCE: my 2000 blazer won,t select 4wd hi/low or auto

there is a vacuum solonoid on the firewall in the middle with 2 vac lines and a 2 wire plug
thats ur problem
push the button and smack it with the handle of a screwdriver should work

SOURCE: 2001 Dodge Durango stuck in 4 wheel-Low. Won't switch back to 2WD

Just to clarify, the "transmission" is not stuck in 4-Lo. It is the "transfer case" that is attached to the transmission that actually engages the 4-Hi and 4-Lo modes. To properly shift your vehicle into 4-Lo, you know that you have to shift the transmission into neutral and slow down to less than 5 mph. Once your vehicle slows down to this range, your can switch your transfer case into 4-Lo mode. Due to the inner workings of the transfer case, the actual shift into 4-Lo may take a few seconds to complete. This is normal and does not signify that there is an issue. All transfer cases that have 4-Lo mode will act this way regardless of the make or model. To make a long story short, to shift out of 4-Lo you must follow the same steps that you took to shift into 4-Lo, just in reverse order. Switch the transfer case to 4-Lo mode if it isn't already there. Slow down to less than 5 mph (your vehicle must be moving, though). Then, shift your car into 4-Hi or 2WD. Give your vehicle several seconds to complete the shift. The transfer case indicator light will flash until it is complete. When it does complete the shift into the new gear mode, you will most likely hear a "clunk" (the range sleeve inside the transfer case disengages from its mating spline) from under your car. Again, any transfer case with 4-Lo (regardless of make or model) will exhibit this same noise. This should help you get out of 4-Lo. It is good practice to shift your car into and out of 4-Lo at least a few times each year to keep all of the splines free of corrosion and build-up. Based on the age of your vehicle, your transfer case may also need a complete flush and some new transmission fluid. Hope this helps.

SOURCE: service 4wd light

what causes the 4wd to kick in when you have it in 2wd

SOURCE: Stuck in Lo Range 4WD. Suggestions?

Try key in run position(without starting it) and try to shift it into 4wd high with the shift lever in neutral.