I got a 1997 blazer 4x4 4.3l from a friend to fix up got it all in great shape but the 4wd just wont work. no lights on the 3 button switch. 20amp fuse is good, tccm I just replaced as well as the 3 button switch. I have been front to back on this thing and cant figure it out. I have been trying to find a tccm wiring diagram but no luck for my 97, I have power to the axle switch on the pink wire, I have power to the 3 button switch, and power to the orange wires on the tccm, ground wires I can not figure out. please help..

 

Do you hear any kind of sound when pushing the 4x4 switch?

 

no sound at all

 

Hang in there There are a ton of guys on here, christine 208, cleburne red, odat, transman just too name a few that really know their stuff! I have no doubt you will get some help soon

 

thanks

 

If 1997 has a BCM (can't remember), it supplies the power for the status lights and TCCM the ground

https://blazerforum.com/forum/2nd-gen-s-series-1995-2005-tech-41/nvg233-rpo-np1-4wd-transfer-case-info-2001-blazer-89670/

 

no bcm on my model. just ecu located on pass. side under hood and tccm located by the flasher relays under dash below the heater a/c controls.
so far I have looked at all diagrams online and none of them match my 97.

 

I looked at your link. I have tried the pin 13 ground test. when I do that it still does nothing no lights at all on switch. when I put a light tester on a ground then touch the wires on the back of the 3 button switch depending on which wire some light up others if I push 2hi 4lo or 4hi they light up test light.

 

wouldn't that indicate that the tccm is not providing the ground for whatever reason.

 

That's what I thought which is why I just bought a new one and still no luck