Hey all. I have a 99 F150 4x4 XLT. My four wheel drive is not working. I turn the switch and the light in the dash says its in four wheel drive but its not engaging. I noticed that in the middle of the underside of the body there is a canister with some hoses coming out of it. One of the hoses was laying on my exhaust and now has a big hole in it. Would this have anything to do with my issue? It does shift into low range just fine but still no 4x4.

 

It would depend on where the "canister" is located. Try the Vacuum Control Solenoid... cheap fix if the 4wd aint engaging. it happedned to me...