Hey guys got a 5.4 l f150 4x4 got no 4x4 light when turning switch all fuses are ok just stopped working out of nowere no 4x4 engagement or clicking of any sort... any help isnappriciated 4x4 hi andlo come in during bulb check any help isnappriciated thanks!

 

two parts to the 4 x 4... FIRST the transfer case motor moves and engages the front drive shaft... ( this can be LO or HI) .......... second, the vacuum solenoids on the firewall shut off vacuum to the wheel ends and the engagement is locked in for each front wheel........... So if you put the truck in 4 x 4, then shut off the motor you should not be able to turn the front driveshaft by hand ( crawling under the truck)... you can jack the front end off the ground and try to rotate one wheel.. The wheel should be locked in 4 x 4 ( loss of vacuum) with motor off. If you can turn the wheel, see if the driveshaft is rotating also. If it is, then the transfer case motor is not locked in... If you cant turn the front wheel, then the wheel end and the transfer case are both locked into 4 x 4.

 

Yea neithet my vac solenoid nor my transfer case motor engages..... and it was working perfect 2 days ago.. does the switch often go bad? Or is there a t case relay i should be checking..

 

All fuses are ok front drive shaft def no.locking nor are hubs... thanka.for any help.... im not aure the logic i cant find a wiring diagram i assume from.siwtch there must be a relay for hi and one for low.. or a control module or aomething im missing

 

I believe the power goes to the shift motor and it moves, THEN everything else starts to happen. If the motor does not move, then your dead in the water. I would check voltage at the motor plug, then remove the motor and plug in and test setting on the floor, etc.

--- thinking about it more, the most common problem is sticking of the engagement pistons at the front wheels... jack up the front end and turn the tire and see if they are locked to the drive shaft FIRST..

 

your front end should have a vacuum hose at each side behind the hub... there is something that looks like a big vacuum cylinder that pulls the hub out of 4 x 4... when the motor stops, you should be locked in 4 x 4 at the hubs. When the motor starts, vacuum pulls the 4 x 4 OFF, unless you move the dash switch. .......... I will post a link you can read.

 

https://www.ford-trucks.com/forums/8...then-some.html

 

Correct, there are a series of contacts within the motor that control the 4WD relays and the dash lights.