I have a 2003 Silverado 4WD. When I push 4H, the light comes on but I don't hear it shift and the 4WD doesn't work. The 4H Auto does work however.
The 4L works also.
I took out the switch panel and checked the ohms for each switch and all are in the correct range according to the info I found on the internet.
Is there some place other than the switch that I should be checking?
Can the switch be bad even if the ohms are in the correct range?

 

This problem hasn't gone away. I put in a different 4WD switch in the dash and I still get the same problem. Can there be a problem with the actuator even though the 4WD Auto and Low work? Thank you