Nissan Repair: Air / Heater switch works only on high, case purchase, glovebox

Question
My air/Heater only works on high. I replaced the unit but still have the same problem. What controls the speed of the blower for the temperature setting

Answer
Emilio,

The blower resistor needs to be replaced.  On the passenger side, under the dash, there is a resistor cluster that the blower harness connects to.  There are two screws that hold the resistor cluster on the blower case.  Purchase a new one and you will see what you are looking for.  Remove the glovebox and look to the left of the case, close to the center and you should see it.  Just a couple of screws and unplug the old one and install the new one.  If the car is off there is no need to disconnect the battery.