Hello happy Raptor owners!! First time post and it pains me to have to have a first post like this. I did search for my particular problem before posting this but I'm not finding anything exactly related to my current problem so here it is........I just bought my Ruby Red 2019 Raptor a few months ago and love it!! I traded a 2018 Lariat for it that was having what sounded like a wheel bearing issue that nobody to could diagnose....which leads me to this post. Now, I understand it's a Raptor and it's got low gears and if you can afford one, why worry about gas mileage, right? So when trying to diagnose my Lariat problem, I asked the mechanic riding with me if it was possible for the front axles to be making the noise I was hearing and he said "that's impossible because the front axles don't turn while in 2WD". I'm always interested in seeing how things work, so I take the truck home, jack the front up, start the truck in 2WD and what do you know....the front axles are turning just like he said they wouldn't. So I do some reading to figure out how this IWE system works and find that the vacuum solenoid is not opening as it should and not unlocking the front hubs as it's suppose to. Now....fast forward to the Raptor since I traded the Lariat for it.......I rotated my own tires the other day and thought.....what's the chances the axles turn on this one in 2WD too. Sure enough, I fire up the Raptor, spin the front wheel and the axle is turning! I'm very puzzled. So here is what I did......I unhook the solenoid totally and just plug the vacuum hose directly from the check valve to the hose leading to the IWE's on both sides. Think I'm crazy but with the hubs actually unlocked and not spinning that extra drivetrain weight, I went from 16.3 mpg to 17.5 mpg going to work with the cruise set at 75 as always. What a huge gain! I don't quite understand how the solenoid system is suppose to engage but something seems out of place. I tested the plug and it's showing 12.56 volts to the solenoid....perfect! here's the issue though.....I turn the truck on (not starting), I go out and blow through the bottom vacuum port and the valve is open like it should be. If I start the truck, the solenoid valve is closed and not pulling vacuum on the IWE line at all. Can anyone please explain to me why starting the truck turns the solenoid off??? Maybe there's something else that takes place while driving that finally opens the solenoid again??? I'm not sure what series of actions has to take place in order for this to work properly. I'm convinced that the IWE solenoid is not pulling vacuum at all otherwise my mpg wouldn't have went up. I thought the ground was bad to the solenoid so I shave off enough wire coating and use a pair of alligator clips to ground the wire properly and all the sudden, while the truck is running, the axles are not turning and the solenoid is working again. All good until I get in the truck and and the dash has a notification about 4WD system failure! I unhook the ground I made and it goes away but then the solenoid closes again as well. So here's my fix option.....I'm going to use one of the auxiliary switches and run a positive connection to the solenoid and ground to the body at the closest firewall ground, order a pigtail so I don't cut up the factory plug and power the vacuum solenoid located on the drivers side firewall with an auxiliary switch. I leave the switch on to power the solenoid and unlock the hubs and when I need 4WD, turn of the switch and use the 4WD selector. Is this a good idea or bad? I know that if I go to the Ford garage and explain to a certified mechanic what is wrong and how it should work, I'm going to get laughed at and likely never get a resolution to an existing problem. I know Ford has had it's failures with the IWE issue and maybe I'm going out on a limb to say that the system is meant to fail so that the front always stays engaged so that the clicking noise never happens to current trucks? I mean c'mon.....you buy a new truck, who jacks it up to see the the hubs actually unlock? I only did because I was told it doesn't turn in 2WD and I had to see it for myself. Sorry for the long winded message but I'm aggravated over the issue and hoping someone else has seen all this too.