[bigrodrosin]

2003 f350 4x4, superduty, 4-door, I changed it to warn manual locking hubs when purchased 4 years ago, esof hubs were toast. from the time I got the truck the 4x4 would stop being in 4x4, even though the light on the dash would say it's in 4x4. this is the first snowy winter we have had here since I bought the truck, so here's the issue.

warn hubs are locked, turn selector switch on the dash to 4x4 and the light in the dash comes on saying i'm in 4x4, but no 4x4, turn the selector switch back to 2wd and back to 4x4 and it engages, may have to toggle 3-4 times for it to work. once it goes into 4x4, just driving down the road it would stop being in 4x4? I checked the servo motor and when I took the plug off there was oil there. not a lot, but it was there. I previously read this to mean the servo motor is bad. so I bought a servo motor. yesterday I installed the servo motor and now I have nothing? toggle the selector switch and no 4x4 light in the dash. no audible action at the servo either. checked fuse 17 and it's good, switched all the relays under the hood and still nothing. can anyone help? my only vehicle and have to have 4x4 by tomorrow!

 

[mouseys_7.3]

Are you getting 12 volts at the servo connector? Have you tried 4x4 low? Could the be the selector switch has failed.

 

[bigrodrosin]

no voltage at the servo, voltage comes the 2-pin connector right? no voltage at the selector either? to me everything screams burnt fuse, but fuse 27 is good, is there a 30a fuse somewhere that I need to check? or any other fuses?

 

[bigrodrosin]

needing help

is anyone around that might be able to help, just trying to not spend a fortune at the repair shop.

 

[mouseys_7.3]

wiggle the fuse and see if that works. Have you pulled the fuse and checked continuity? Its almost impossible to see if a fuse is blown while inserted. And can be hard even with it in your hand.
Another thing, try "massaging" your wiring loom. Had that get me out of a jamb before.