what are some ways to determine what is wrong on my 4 wheel drive module or shift motor? i have the 233 TC (3 button selector), i already replaced the vacuum switch and the actuator looks to be working right. when i push 4hi i hear it start to engage, then all lights go out on my selector. i tried putting it in reverse and the truck didnt even move, further more i put it in park and i heard a grind noise after a few starts i finally did get it back in 2wd by pushing 2wd button i heard a clunk and 2wd lit up on my selector. is my shift motor bad?

forgot: the lights flash indicating the selector works every time i turn key but all go out after

 

In the tech section there is a thread to help diagnose 4x4 issues.
sounds like it is not engaging though.

 

the tag on the back of the TC reads "New Process Gear 233-C" how hard is it to replace the motor?

 

I wouldn't think the TC is bad....keep checking! My blazer did some funky things when the switch (3 button selector) went bad. Soldered the switch back to the circuit board and everything was fine after that.

 

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UPDATE: i just went out and tried it. started the truck, put it in drive, once it started rolling i shifted to N and pushed 4hi i heard it engage and could feel it in the truck, both 2hi and 4hi were lit up on my selector. i shifted to N again and pushed 2hi, both 4hi and 4lo blinked 4-5 times then 2hi lit up. i could hear it disengage. thoughts?

 

any suggestions??

 

bump....

 

Give this read a shot my friend.

4x4 Diagnostic Truck and Blazer - Drivetrain - Zr2USA.com

 

UPDATE: thanks for the info brother. i tried it again (rolling) it started to shift then lights went out again, no reverse at all, put in drive and grinded under truck. i quickly shut motor off, and jumped the pins on ALDL. got DTC 2 on transfer case, advice please

 

Not a unit repair guy. Anybody else?