I have an issue with the 4x4 shift motor/control on my 08 F250 6.4PSD.
It started with the 4x4 High light coming on randomly when I'd hit a bump in the road. Hit another bump, it would go off. Now it is on pretty much on all the time. Bought a new transfer case shift motor assembly and have done some trouble shooting. It appears that a wire from the position sensor to the controller for the 2wd position is broken. I've taken the shift motor off the transfer case and have verified it works without issue switching between 4x4 high and 4x4 low. The issue is when I shift to 2wd, the motor by passes the 2wd position and just drives until it bottoms out internal stuff on the shift motor gear box. The 4x4 light stays on. Does basically the same thing with the new and old shift motor assemblies. Have also replaced the 4x4 motor relay under the hood. Any ideas where to check for the electrical gremlin I appear to have?