so my 4x4 will not engage. 4H or 4L. any suggestions? i've tried putting it in park putting it in neutral and driving at abt 15 mph. it wont go into 4x4. it's a 2001 f150 screw 4x4 with 140xxx miles. help!!

 

Do you hear it trying to lock in, do any lights saying its in 4x4 come on?

 

yeah. lights come on and i hear the clicking noise in the dash

 

yeah. lights come on and i hear the clicking noise in the dash

 

Do you have the manual shift or push button electronic shift?

Sounds like you may have a solenoid issue. There is a really good thread on the 4X4 system on here that walks you through the diagnosis and everything.

 

electronic shift. how would i find that thread?

 

First would be to see if you have vacuum running from the solenoid

 

I wish I would have saved it. I haven't been on here too long, maybe one of the long-timers can point you in the right direction. It was a complete comprehensive break down of diagnosing and repairing the 4x4 system, good read.

The gist of it is: switch, power, vacuum, solenoid transfer case... Trace the problem in that order and it should help you find the solution.

 

I agree, that was the problem with mine, but i have the manual on the fly shifter. i replaced those vacuum lines and worked perfectly.

 

I had this problem as well when I first bought my truck. It ended up being a loose vacuum line. From what I've seen on here and my personal experience I'd say check the lines first because you have power to the switch and the truck thinks it's engaging.