I have 2004 f150 with 60000 no more warranty on it. I tried to use my 4x4 last week up in the snow and the front wheel will not lock. I had the light on my dash on. That it was on 4x4 but my Hi/Low won't engage. After a little research found out that this ford have problem with this issue "IWE". I think is the IWE because I have vacuum in the connection on the IWE. Has any body change this part before and is there any forum as of how to replace this.

 

Dang, I am not the only one huh ?? I have an 04 4x4 with the same problem. When I try to engage the 4x4 the high lights up but not low and it won't engage.. Hopefully someone on here can help with this problem that sounds like it SHOULD be a recall to me !!!!!

 

I had the same problem It turned out to be a broken rod in the transfer case I only had 13xxx miles on the truck when this happened I had a ford esp and it only cost me $100.00 The total bill was $690.00

 

Happened so long ago but I think it was a relay...Then another time it wouldnt unlock and it was the fuse.

 

If it is an old body style and not a new body style, then you could just have a vacuum leak. The default position for OBS is unlocked and NBS is locked