i have a 1990 cherokee with the np231 and when i step on the gas my parttime light goes off but when i let off it comes back on?? the light is on at all time? thanksss

 

I just rebuilt my whole vacuum 4x4 system, T/C switch, all plastic hoses, axle motor. Still didnt work, even though all those parts WERE bad. My steel lines along frame were plugged. Some how the elctric switch near the blower motor is getting vacuum, not much though, because as soon as you open throttle, vacuum drops and the light goes out. Stuck/sticking T/C switch maybe? You can get them on the HELP isle at the parts store, cheap around 20$.
Does the vaccuum motor actuate when the T/C lever is moved?