No4x4 - 2002 Chevrolet S-10

I own a 98 short box S10 4X4 with a Vortec 4.3 and a posi rearend. I have had to check all these areas of the 4wd system. Could be one of the following or a combo of more than one __1. the fuses 2. the actuator (under the battery tray) 3. the cable from the actuator to the front differential 4. the transfer case control module (behind passenger side kick panel) 5. the vacuum switch (on top of the transfer case) 6. the push button on the dash.7. cracked or dry rotted vacuum lines in the system. Any of these not working properly will prevent you from getting your truck into 4wd. My issue ended up being the cable and the actuator. I had a vacuum issue which would not let the actuator pull the cable to engage the front axles.Replaced the vacuum lines and the vacuum switch and still no 4wd.Turned out to be the actuator and the actuator cable. Fixed that and now I have 4wd any time I want. If you hear a clicking sound at the transfer case,its fine. If you hear another click at the TCCM, its fine. If all your lights work on the dash switch, its fine. If your actuator doesn't leak any air, its fine. I replaced the vacuum switch for $15 at advanced auto parts. Turned out I didn't need it. I don't drive my truck unless there is a lot of snow so I just locked the front differential until I get a new actuator $30 and actuator cable $30. This was how I fixed my problem and I hope this info can help others,