Ok I have a 2001 Chevy Blazer with the NV236 Auto trac t-case. My problem lies in the TCM I believe, When I push any of the buttons(4hi,4lo,2hi,auto) the light will flash and I can hear the control module in the kick panel clicking and then TCM runs but doesn't move, then the light will go out. I pulled the TCM out and put the 4 wire pigtail to battery power(black wire to ground, red wire to 12 volt positive, and 12 volts positive to the other 2 wire individually to turn both directions. Out of the Vehicle the TCM turns with 12 volts so I tested the pigtail that it plugs in to and only got 6.52 volts. My question is, what is the actual voltage suppose to be and where else should I look for the problem? Thanks Guys.

 

should have 12 on the motor side. sounds like tcm may be bad, ive got the xact truck, they get water in the tccm all the time and go bad. check all the pins and the case for rust. u can buy them now in the aftermarket look into dorman.com. swartwik, sorry if i spelled that wrong no disrespect, has a beautiful write up in the diy section of this site to diag this system to a t. hes done some nice ones thanks by the way for putting all those up! great info