4auto indicting when in 2h

[Aldfaa]

Looking for help with my 08 Eddie Bauer EL. The dash indicates that 4x4 auto is engaged when in 2H. The background is that the alternator started whining, and was extremely hot. Unhooked the battery and replaced the alternator. I also went ahead and replaced the water pump as it was original so why not. Once it was back together I noticed two odd things, once it was started. The fuel gauge was indicating empty and the dash said 4auto. I filled it up with fuel and the gauge started working as expected. I drove it for a bit, switched into 4low and that indicated correctly, went back to 2h and it is back to saying 4auto.
Ended up pulling the transfer case motor and noticed that when switching from 2h to 4a or to 4h the motor would not physical rotate. However In 4L it would move about 180 degrees.

Went ahead and bought a replacement ford actuator, installed it and it acts the same way.

Any other ideas on what to check before I take it to the shop?

 

[Aldfaa]

Did some more investigating, with vehicle running g switch In 2H indicator light shows 4auto. No vacuum on front hubs. Checked hubs with a vacuum tester and confirmed that the iwe would hold vacuum of 20 for several minutes on both sides. Went up to the iwe solenoid, and verified engine vacuum on bottom vacuum fitting to solenoid. Removed upper connector and no vacuum through solenoid. Checked voltage at solenoid wiring and I have voltage. For good measure checked vacuum from solenoid down to hubs and that held. If I manually hook up the solenoid to the battery it will click and allow vacuum through the valve.

 

[Aldfaa]

Alright, think I finally got it figured out. I pulled the selector switch and measured resistance on pins 2 and 3. Every position read correctly except 2h. Was reading 33000 ohms in that position when it was supposed to be 620. Using some resistors I had laying around i installed them on the switch connecter duplicating the 620 ohm load. And the truck went into 2h.

 

[Mark Buckner]

Alright, think I finally got it figured out. I pulled the selector switch and measured resistance on pins 2 and 3. Every position read correctly except 2h. Was reading 33000 ohms in that position when it was supposed to be 620. Using some resistors I had laying around i installed them on the switch connecter duplicating the 620 ohm load. And the truck went into 2h.

Thanks for this information so I will know where to start if I ever have this issue. So is the fix to replace the 2WD/4WD selector switch?