my 4 wheel wont engage. it worked one night and the next day nothing. I tried to pull the cable to engage the rear and it made no difference, Also I can hear the transfer case engage but no forward pull off front tires. Can anyone give me any ideas of what could cause this? I already have a new actuator to put in along with new cable and transmision switch

 

Most likely a vacuum line disconnected/broken. Verify you get vacuum in 4x4 at the actuator located under the battery tray. If not, check the 4-way splitter near the distributor to ensure everything is hooked up, and then trace the vacuum lines to see where the break is. If no breaks, you may have a bad switch in the t-case, or improperly connected switch in the t-case.