HELP! 97 Limited 4wd not engaging SUGGESTIONS

4wd will not engage. My limited has the two position TC with the 4wd engage push button. I get nothing when I press the push button on the shifter. No usual click from the relay/ecu and no actuator running sound either. The indicator light does not come on. The 4wd fuse is good. I verified the front axle does not lock in (spins freely). The VSV’s do not swap automatically, but I don’t think they’re ever getting the signal to swap since nothing happens from the push button. I did verify that the front axle does lock in when I manually swap the vacuum hoses at the VSV’s. (Does not spin)
I am leaning towards it being my 4wd ECU as the issue. Any other advice would be appreciated.
also, help me locate the 4wd ECU on my runner and electrical prints. Online Resources are sketchy on that.

thanks,
Brian

 

Any OBD codes?