Problems with shift on the fly. Need help

[JACONTRACTORS]

I am having trouble with my transfer case. It started Monday. When I turned on 4high I lost climate control functions. I found a bad vacuum line at the passenger side hub. Fixed it and that problem was solved. Went to work later and now I cant get the transfer case to switch back to 2 high. The shift on the fly switch does nothing. I unplugged the switching motor harnesses and removed fuse 28 in the engine comp box then reconnected everything and was able to shift into and out of 4low one time. So I am back to 4high. What should I be testing to figure this mess out. Can someone please give me some good starting points. Thanks in advance.

[NCHornet]

Sounds like the hubs just need to be cleaned. Next time you shift back in 4x2 and go backwards 15-20 ft and see if it unlocks. It could just have been in a bind.

NCH

[speed_racer_801]

When I was going through all of my 4WD issues, I found an open circuit on the wires from the GEM to the tcase shift motor