Blower heater fan only works on 4, 1,2,3,and 5 don't work

Blower motor relay , resistor , control module . any one of these could be the culprit . You have to test to determine which one is at fault ! Do you have a DVOM - digital volt ohm meter an do you know how to use it ? Heater Blower Motor Troubleshooting Blower Motor Problems Auto Repair Help

replace with this and it will work. Heater Blower Motor Resistor 2003 Chevrolet Trailblazer 2WD 8 Cylinders...

check blend door acuator

either bad blower motor resistor (least expensive fix to atempt) , or blower motor bad or electrical circuits to motor

a couple of things,1 blower motor fuse.2 blower motor gone out.3 switch on fan speed control switch not sending signal to fans.after checking the fuses.next check theswitch on control panel.set ac or heater.if fan still doesnt come on then replace it.when it work and then stops working there are a lot of possiblities that caused the prob relay too not fliping over inside staying close loop.hope this helps.

if automatic heater and air it will be inside the blower motor

you might check your switch sounds like to me that your two lower speed sides of the switch maybe burnwed out.

none of the controls are working? or just the fan control? if it is just the fan control, your problem is the blower motor resistor. it is located on the airbox, close to the fan motor.

these vehicles have a heater control resistor mounted to the heater box. This is the module that is used to reduce the speeds to the blower motor. you will need to replace it. it is located next to the blower motor,

Your blower motor resistor has gone bad, it should be located next to your blower motor in the car, held in place with a couple of screws, remove it and replace it. The resistor is responsible for making the blower motor run at slower speeds than high or (4). Let me know if this helps.