i have 2000 blazer. 4wd has been inoperable for about a year. tried a new dash switch...didnt help.

when i turn on the key no lights come on the switch. after about five seconds the tccm clicks and the service 4wd light comes on. any ideas??

Use the troubleshooting sticky on the forum. Also use my findings by pin to help. It might help you find the problem. A new TCCM I found on Ebay was 150.00. Do not know what they sell for elsewhere. I would troubleshoot first instead of just buying a TCCM. It might be an issue with the transfer motor unit. Hate to throw money and parts at a problem until it is fixed.

Andy