99 Blazer Vacuum Axle Actuator

My Blazer transfers from 2HI to 4HI and back. However the vacuum axle actuator does not release. If I disconnect the vacuum line it releases. Lately I have gotten a visual on the dash to service the 4x4 system, the lamps flash on the selector switch and the relay's click. Any idea's ?
Found the cure the vacuum lines were reversed at the switch.