When I lower my blower fan switch to off position it stays on low speed. I have a continuous knob not one with set speeds. Do I need to change the resistor or change the whole ac/heat control unit with the 3 knobs?
Lets take a look at the wiring diagram of the blower motor circuit.
Blower motor wiring diagram 2011 Jeep Wrangler
After looking at the diagram it would appear this vehicle uses a Power Module instead of a blower motor resistor. But this would be my first guess at to what needs to be replaced.
Manual or Automatic Climate Control?
Yes, both the Manual and Automatic temperature control heating-A/C systems use a power module to control the the blower motor speed. The power module uses a Pulse Width Modulated input from the A/C-heater control and a feedback signal from the blower motor to regulate the blower motor ground path. On both systems, the blower motor receives battery current through the Totally Integrated Power Module whenever the ignition switch is in the RUN position, and the blower motor control is in any position except OFF.
The blower motor can be accessed from underneath the instrument panel and is diagnosed using a Scan Tool.