actuator electric problem

[ev1001]

my 4wd will not engage have replaced thermal actuator and I know the actuator is the problem cause when i hook it up and turn the key on it does not expand while out of the differential.   I tested voltage at actuator plug 11.6V.  The switch seems to be ok; when I select 2wd I get no voltage reading.  Could the switch still be bad since i have a low voltage or is the problem in the ground?  have no other electric problems other than wipers quite working if it rains sometimes.  If the actuator switch, where do I find it.  If a short where would I look for it.  I followed the wires from the actuator and go to the front cluster in the eng compartment and I loose them there.  Any help would be apreciated

 

Thanks