4x4 not working need help


Hello all I am having a problem with the 4wd on my fourtrak f73 rocky we have recently done a clutch change on it and when pressing the 4wd button nothing is happening I have read online about there being a possible vacume hose i have puller the gear stick surround up and noticed 2 circle boxes unterneith with 2 wires from each at which 1 has a wire off could that be the problem or what are they.