2005 Chevy Surban blower motor resistor

The blower motor relay is energized when the Blower Motor Control is set to the High position. This removes the blower motor resistors from the circuit and battery voltage is then applied directly from the HVAC BLO fuse (RH IP Accessory Wiring Junction Block) to the blower motor though the relay switch contacts. The blower motor then runs at high speed.

HVAC Blower Controls Circuit Description
The blower motor is a variable speed motor. The motor operates at a higher rate when voltage is increased to the maximum level.
The blower motor resistors reduce the voltage supplied from the A/C FAN fuse (LH IP Accessory Wiring Junction Block) when the blower control is set at low and medium speeds (speeds 1-4). The blower motor relay is energized when the Blower Motor Control is set to the High position. This removes the blower motor resistors from the circuit and battery voltage is then applied directly from the HVAC BLO fuse (RH IP Accessory Wiring Junction Block) to the blower motor though the relay switch contacts. The blower motor then runs at high speed.

Did you check to see if you are getting power to the blower motor ?

That depends on WHICH speed sensor you want to change. The Vehicle speed sensor? a front wheel speed sensor? A rear wheel speed sensor? an input shaft or turbine speed sensor?

Hi, the blower module that is located at the bottom of the heater box, next to the blower motor, above the panel below the glove box, has a tendancy to go bad, possibly overheat, and melt the larger of the two connectors. This can lead to one or all sppeds inop. the module will need to be replaced, and th connector inspected. If the connector is melted, or discolored, it needs to be replaced. A pigtail with wires, and connectors, as well as the resistor, should be available at a local GMC or Chevy dealer. Good luck...Coop

Common issue for many cars, Jeeps big time. Your "Blower Motor Resister" is defective. The reason for only 4 on the speed is the resistor controls the voltage going to the blower motor on the lower three speeds. This is a common problem, don't let anyone tell you it is the blower moter itself. The part should cost between $20-$40, depending on where purchased. The killer is getting it installed, some are easy to get at behind the glove box, others are up in the dashboard harder to get at. Chevy techs should be well aware of this, and be able to give you a good estimate of repair.

I had a truck about the same year with the same problem, it was the wiring harness, but id check the resistor and the fan first before replacing anythings,

That's where I'd spend my time & money.Resistor.

It sounds like your blower motor may be bad. I don't know if you know how to check power at your blower motor plug, but you can use a volt/ohm meter or a test light. If you have power (12VDC) , your motor is most likely bad. There is also a resistor block module which has 2 resistors on it. It controls the motor speed basically by restricting the power by directing it thru one of the resistors. The higher the resistance, the slower the motor turns, thus the 3 speeds for the motor. The resistor module is mounted on the blower housing and has 2 screws holding it in with a small plug connected. It is just about straight ahead of the passengers left knee.
You can get used motors from a junk yard pretty cheap.
Good luck

need blower resister for blower.

Good call emissionwiz. It's right behind the blower motor, under the glove box area. Remove the shroud below the glove box, 2 screws and a snap-pop fitting. Be careful of the courtesy light. Remove the blower moter and disconnect the purple/black power connector to it - - you'll need this extra room to work with. 2 more screws, same size, 6.5mm on mine, 7or 8mm on some others, that holds the blower motor resistor in place. This replacement part is less than 40 bones at most parts store. Unplug, replace, re-install, test and you're on your way with about 2 hours of slow paced effort in your own driveway. Typical cost at a garage - up to $400, what a sham.