Ford: Correct procedure switching in and out of 4wd low

Question
QUESTION: Good afternoon Brian,

I have a 2004 F-350, 4WD, 6.0 Diesel, FX4 dually.  I recently spent a day off road where I went into 4wd high, 4wd low and back to 2wd many times throughout the day.  The following day I needed to switch into 4wd low to make pass through a rough area and when I went to adjust back to 2wd, the vehicle remained in 4wd low.  I have manual hubs and have tried many times so far to lock and unlock them and the OTF shifter back to 2wd with the truck in neutral as well as park.  I even rolled it both forward and reverse a little to hopefully engage the electronic shifter.  As of now I am stuck in 4wd low.  Could you please give me the correct procedure for engaging and disengaging or any other ideas or possible failures to look at.  Thanks for your time.

ANSWER: Start with the switch in the 4 low position key off. Set the parking brake. Start the vehicle shift to neutral,  with your foot on the brake shift out if 4 low to 4 high then to 2 high

---------- FOLLOW-UP ----------

QUESTION: Thanks for the rapid response Brian.  I went through the motions, as you suggested.  Actually, I tried this various times and am beginning to think it's time to start pulling relays to see if they are wet and if so, hopefully they will dry.  Worst case scenario, I would imagine the transfer case solenoid got wet and ended up shorting.  Any other ideas or input you can offer me?  I don't have a book on this truck and am not sure where that solenoid is located.  Could you point me in the right direction?  Thanks again.

Answer
The 4x4 solenoid is located under the hood on yours in either of two places. Mounted to the fan shirts or against the firewall left side looking at it.  First though , check the fuses. There are 7 of them that control various parts of the 4x4 in the fuse panel by your knee.  It's possible to that there is a problem with the shift motor. I know it sounds brave, but have a friend lightly tap on the shift motor on the transfer case while you perform the exact same procedure