On my 2001 2500 hd plow truck i pushed the 4x4 button and all i got was 5 flashing lights on the button and then it went back to 2x4 . I can hear an electric motor noise when i push it , at the transfer case just does not seem to engage . Any ideas where to start ?
Thanks

 

maybe a few things. you should see if there are any codes.

 

Had the same problem on my 91. it was not the transfer but the front axle accuator.
Cost me 30 bucks and 30 min to replace.

 

could be a couple things... front actuator already talked about and also i read about the switch going bad in other posts. I have the same issue in my 04 2500. I'm on deployment right now to troubleshoot the issue.

 

Check ground wires under drivers door outside frame looking forward. Clean wires and frame and tighten securely. Check and clean all connectors on T/C, forward axle and dash switch. Good place to start.