Just installed new vacuum pump and 4x4 still won't lock in. When I turn the switch on the dash it starts blowing out the defrost. Checked the switch on the firewall next to the pump and it started to blowing out the vent again but still not locking in when you put it in 4x4. Checked all fuses and they are good. 2005 F-250 6.0L Is there a motor on the trans. and would this cause this? Also switched hubs to manual and nothing happened.
