rockfiend

i have a 96 5sp 4runner and my 4wd stopped working after a few months after purchasing it...i searched alot before posting.
short version is i checked everything i can think of and all the stuff the other people had posted. switched the 4wd solenoid with another toyota and mine works on his and the 4wd ecu and tested the front actuators and i can manually make the 4wd engage and disengage by bypassing the blue/brown solenoid. the brown and blue solenoid is what im stuck on. i dont know what/which sensor or relay activates them

my questions is there a constant vacuum pull too the 2wd/4wd solenoid located on the driverside fender wall? mine doesnt. and also is there a relay that controls it. i read a few other post and that might be the problem but i dont know where it is and my last question is which 4wd switch sensor activates them?

any help is appreciated