1991 GMC Sierra 2500 4wd Transaxle Switch

[south]

4wd is working intermittantly. I replaced the actuator. Is the transaxle switch able to be replaced by a switch in the cab. There is a brown and a lite blue wire running to the plug for the transaxle switch.

The 4wd will engage until after running the truck for a little bit, makes me think the switch is heating up and then wont engage.

Thanks for the help.