Spent a good amount of time and money on 3/1 leveling kit, wheels, and tires just to get to beach and get stuck in sand. Front wheels never engaged. Electronic switch activates transfer case and turns drive shaft going towards front end. Vacuum must work seeing as how it will not let IWE disengage. I've narrowed it down to Vacuum Control Solenoid, actuator, and check valves. Searched the website plus countless google searches and YouTube vids. Can't seem to find anything on 12th gen f150 (2009-14). I'm new to the forum and desperately need advice. Thanks in advance.