My 3010 4x4 mule has to be in 4 wheel drive to move why?

SOURCE: 1993 Chevy 1500 pickup 4-wheel drive

I replaced the malfunctioning “thermal actuator” with the “Warn” Vacuum actuator setup, it’s been working great for about 7 years now, simple install, if I remember correctly, it was about $150.
That’s what engages the front diff into 4wd.

SOURCE: 4 wheel low works but 4 wheel high does not.

sounds like the encoder on the side of the trans on the drivers side

SOURCE: 1993 4X4 BLASER 4WHEEL DRIVE

Your blazer is equipped with a shift on the fly four wheel drive. That means that at speeds less than fifteen miles per hour you can shift into or out of four wheel drive by simply pushing the four wheel high button. If you wish to shift into four wheel low. Stop, put the transmission into park or neutral, and push the four wheel low button. Same procedure for shifting back out. Never shift into or out of four wheel low while moving. And be careful in four wheel low. At full throttle your still barely moving, you don't want to blow your engine up!

SOURCE: My 98 s10 is stuck in 4 wheel drive low.

Pull the kick panel on the passenger side. there is a small box mounted there that is the computer that controls the actuator for the 4wd system. this is notorious for problems due in fact that the connector likes to pull out and away from the module. I had the same problem and the solution is simple.. take a long zip tie and get it between a few of the wires and around the module. tie it in and have a nice day.. it wont come off or try to pop out anymore and you should have no issues getting into 2wd, 4wd h, 4wd L.

SOURCE: 2004 jeep liberty stuck in 4 wheel drive low -

a reluctant transfer case can sometimes be coaxed by shifting into reverse, backing up 10 feet, and then back to forward.