Fan motor only works on number 5. ? - 1990 Nissan Minivan

if you got heat on all speeds and the blower motor is working properly then you probably need a new HVAC switch.

Its called the blower motor resistor!! This controls all circuits to the blower motor (a/c fan) and regulates speed according to the switch/fan selector. Some issues caused from a faulty resistor may include: some or all fan speeds don't work, fan cuts out, no power or intermittent power to the fan motor.

Most likely the ignition swich.

Probably need to replace the heater motor resistor.

you need to replace the blower motor and the blower motor resistor to correct you problem

blower motor resistor goes bad, be sure to check for a burned ground wire and repair if necessary

Replace blower resistor pack, located behind glovebox mounted on blower motor. Also check for burnt wires or contact pins on connector.

A bad blower motor resistor will cause it. It is located ny the blower motor p.s. below dash.

You will need to replace the blower speed control, it is shorted.

replace the resistor 4 the blower motor that should slove that hope this helps