Hello all. New to this forum but having the same issue as everyone else with the IWE. One catch though that I haven't found an answer for. Mine was intermittent and predominantly only in the AM.
Bottom line up front, I have constant vacuum from the engine (~26 hg) and just replaced the solenoid. Problem remains. So, I checked the solenoid and its good. Then, I hooked up a test light to the circuit going to the solenoid and drove around a while. Occationally, the light goes out, vacuum drops to zero and grinding begins . A few seconds later, light comes on, vacuum comes up and noise stops (old solenoid was good too turns out). My problem is the power to the solenoid is intermittent. Also discoverred its on the same circuit as the AC clutch.
Anyway, fuse is good but for some reason the power to the solenoid occationally turns off (then back on a few seconds later).
BTW 2006 F150 Lariat Crew 4X4 w/6" lift
Thanks in advance.