2003 Silverado ac/heat blower does not work

HVAC climate contol , Heat an A/C blower motor not working ! The blower motor works for both heat an A/C . Manual or automatic climate control ? Blower motor is bad or blower motor control module is . videos on youtube on testing blower motor electrical circuits .

First check your coolant level. If the coolant system is full, then it is probably the passage doors inside the heater/AC case not operating properly. A door or its actuator has a malfunction. Most actuators are vacuum controls, although some are electric motor operated. Turn Heater on and set temp. control on high-this should cause the actuators to respond by opening some inner doors. So when you turn the blower on, air is forced across the heater core (the little coolant filled "radiator" in the case), and warm air comes out the vents. Watch or listen for the actuators to respond when you use the heater controls. There may be several actuators on the heater case, situated all around, but they are on the outside of the case, right near the inner door they operate.

does the car have automatic climate control?

Do the blower speed settings still work, just weaker? Or is it just one low speed all the time? If you can still change the speeds then it's a weak blower motor. If its just one low speed all the time, (same speed for high and low blower speed settings) then you need a blower motor resistor.

If you have automatic climate control, replace your blower control module, behind the glovebox.
If it's manual, replace blower motor resistor assembly, same location.

If you have manual air conditioning replace the high blower relay
If automatic climate control Air replace the blower module

Well had the same issue on my duel climate controll 04 2500HD but changing the heater control solved the different temp.The only other thing would be your mixer door motor.There are two,one for DR side is probibly stuck..As far as the blower motor.The resister should have taken care of that.Sounds like you may have another bad one.May want to take a volt meter to the resister plug in and run you different fan speed just to make sure that you get voltage to the different conecters.

If the vehicle is equipt with an ambient air temperature display, the sensor also prevents the AC clutch from engaging if the outside air is below as certain tempreture. To test, turn the AC on. Press and hold the AC button at the same time as you press and hold the recirculate button. Hold for 5 to 8 seconds. If this is the cause of the issue, the AC will kick on and you will hear the compressor clutch engage. This should also reset the sensor and correct the issue.

its not a fuse i had the same problem on my 03 x5 it an ac resistor thats at fault it controls your fan once it goes your fan wont come on or comes on intermitently once again the faulty part is a blower motor resistor should be 100 bucs at dealer or if you shop around i got mine for 75 from local parts store (carquest)

Code 23= Blend door feedback control


On cars with automatic climate control: To enter diagnostic mode, set the temperature to 75F, press the the off button. Press Floor, Defrost\Floor, Front Defrost simutaneously for 3 seconds until the temperature display begins to flash.
On cars without automatic climate control, set the blower to any speed, turn the temperature control in between warm and cold. Press Floor, Defrost\Floor, and Front Defrost. All codes will flash via the Front Defrost button.
When the test is over all fault codes will be displayed (on cars without automatic climate control, they will be blinked out on the Front Defrost button).
Code Action
23 Blend door feedback control
24 ATC mode door feedback failure
25 Ambient temperture sensor failure
26 ATC in-car sensor
27 Sun sensor failure
31 ATC recirculate door stall failure
32 ATC blend door failure
33 ATC mode door stall failure
34 Engine temperture sense failure
35 Evap temperature sense failure
36 ATC head command failure