diesel bob thanks for that info I will check it out. this is a message I sent to bob large this weekend

Bob thanks for helping me out on my trooper. I had some time today to trobleshoot the sotf. Its very confusing what is going on. Both solenoids are getting vacum. The gray solenoid is sending vacum to the actuator holding it in 4wd. This I think is all good so far. The blue solenoid does not click on so it doesent send out any vacum out to pull the actuator back the other way to release it from 4wd. I then checked voltage at the plugs on the solenoids and I got 11.9 volts so there is voltage getting to the solenoid but not activating it. I took off the solenoids and tested them by hooking them directly to a battery they both switched fine I could here them click and could blow through them and feel them change to different orfices. the voltage directly of the battery was 12.5 volts. if I connected it back on its plug with 11.5 volts it would not click. this is the confusing part that this little difference of voltage does not activate it. by the way I could not get either soleniod to switch with the voltage comming from the plugs no matter what position the 4wd switch on the dash was in. but could switch them with the voltage from the battery. with your knowlege of the tod system do you have any ideas thank you joh