I just purchased a 2002 silverado Z71 automatic 5.3 with the push button 4 wheel drive. When I bought it the service 4 wheel drive light was on.There were no lights on in the selector switch. After reading this forum and many other articals I desided to replace the selector switch. It did not change anything. I then took the truck to a transmission shop that had the electrical equipment to check all the codes. They determined that the Transfer Case Control Module was bad. They said they could repair it for $800.00. That was a little steep for me so I looked up the proceedure to replace the module and found that it was not that difficult. So I ordered a Module and replaced it myself. I started the truck and the lights on the selector switch came on and the service 4 wheel drive light went off. I turned the truck off and completed some other work I was doing. A few hours later I took the truck for a test drive. In about 5 minutes I smelled something getting hot and all good lights went off and the service 4 wheel drive light came back on. Any ideas?

 

Are you sure you bought the correct module for your truck? Check all the wiring to the module to make sure there are no shorts or bare wire showing.