so i need some help. my electronic 4x4 does not engage. i have replaced the transfer case motor, checked all fuses inspected the vacuum lines and yet still not engaging. so my question is are there any relay's related to the ESOF or 4x4 actuation. if so where are they located. i have a 99 f150 4.6 4x4. if anyone can think of any other reason why it is not engaging please let me know. thanks

 

no one has any idea?????

 

Anyone?????

 

In the engine bay, on the firewall, passenger side, top, all the way against the fender. Two solenoids that control the CAD (Center Axle Disconnect). Could be your problem. The one outboard is the "engage" solenoid, the other is "disengage." I don't know if they're identical, but would think they are. If so, perhaps you could swap them and see if 4x4 engages?

Andy

EDIT: Revised "relays" to "solenoids."

 

both of the center axle disconnect solenoids have failed on my 2000. They are on the passenger side fire wall behind the battery. Pretty easy to change, but you will probably have to order them from ford. As a test, I swithced the hoses from on solenoid to the other and the front end engaged. Replaced the solenoids, and all was well. How ever, a few years have passed, and now my center axle disconnect is worn out. I can no longer shift on the fly

 

i will definetly replace the solenoids on the firewall and see if it fixes the problem, thanks for the help