i have an 04 ls. model type 4.3 v6..4 button style on dash.. no lights at 4 button switch, no noise at tccm, fuse is good, did the remove battery terminal,(also removed fuse),bought new 4 button switch just in case..here's the story...put in 4-low to pull boat from boat launch dock...that was fine...when finished tried to put back in 2-wheel mode lost all lights on switch..now it's like in a neutral state...no reverse, no drive..when i try to put back in park i hear a grinding noise...like its in between a gear mode..i'm totally lost here..it's like no power to switch at dash at all!!

 

"back in park i hear a grinding noise...like its in between a gear mode..i'm totally lost here..it's like no power to switch at dash at all!!"

Or there is a problem with electrics on the encoder motor.

 

be sure to check all the fuses including the one labeled atc

 

i seen the one labeled 4 wheel on the fuse box driver door side..."10 amp fuse" but nothing actually "atc"...location plz

 

big discovery...found the atc fuse....it was blown changed it...but now when i turn the key on 4 buttons flash then go blank again

 

check the tccm behind passenger side kick panel for corrosion on the pins...also can you hear the tccm click when you turn the key on?

 

no clicking or any noise...just the lights on the dash quickly flash

 

-Then kinda sounds like the tccm is not doing it's job...check the pins for corrosion. check for power.
-swap in a junkyard one
-check this thread for more info https://blazerforum.com/forum/tech-a...ill-help-7180/

 

just put another tccm in, cleaned pins and connectors real good...still only a quick flash of lights on switch...no noise from anything...does the encoder motor supply power to the tccm..or is the other way around

 

That sucks,
My wife is the DD of our mini jimmy, but I think that tccm should click every time you turn the key to on, so I think there is still a problem with it somehow.
I think the encoder motor probably gets direct power from the fuse block, but probably is told what to do by the tccm.
I would probably check for power at the tccm....something blew the atc fuse...so I would find the scematic and trace that out

Good Luck