Can anyone help me?? 4x4 quit workin, tryd the switch in a bud's t.b. an it work fine so its not that.. the lights on the switch dont even come on but did in his.. would love sum help. thanx

 

check the fuse. there is one that controls 4wd. might be in inside fuse panel, also check under hood fuse box to make sure they're all good.

 

tryd that first. all were good. checkd em 2 more times since.thanx

 

can anyone hook me up with a wire diagram for this thing?? dat would make a word of diffrence. thanx again

 

K...I got the answer!!!! It was the transfer case control module!!!!!! GM dealer tells me '02 trailblazer and envoy had trouble with these.. trouble with all off them. but mainly in '02. it is an easy change, but expensive part. couldnt find 1 at dat normal part stores. gm only part..$300.00. got 1 out of a smashd 1 at a online junkyard 4 $100. plugd it in and go 2 go!!!!!!! it is up under the dash on da driver side. pull da panal down and reach up under the dash where da parkin brake would b on da older ones. its a littleblack box with 3 plugins!!! change it out.

thanx and good luck