Why is there no power to blower motor resistor?

Blower Motor Resistor

Blazer Forum https://blazerforum.com > forum > blower-motor-resis...
Oct 20, 2010 - The blower motor resistor is located under the hood on top of the HVAC housing towards the center of the truck. Run a search on "blower+motor+ ...

Can't locate Blower Motor Resistor on 1998 Blazer 4x4
Jan 11, 2012
2000 Chevy blazer blower motor won't work on high!
Aug 19, 2023
New blower motor,new resistor, no power - Blazer Forum
Aug 9, 2020
2000 Blazer - Heater blower Not Turning On
Oct 25, 2013
More results from blazerforum.com
https://www.google.com/search?q=2000+Chevy+Blazer+2WD+4.3+V6.+Blower+motor+resistor

High fan speed goes through a relay to power the fan.

Lower speeds go through the resistor.

You will have to check the wiring to see if there is a fault to the resistor, if you do not find one you may need a control head. You did check ALL fuses right?

The resistor provides the ground circuit for the blower motor. So you would need to have power at the blower motor first. Grounding the motor or resistor should make the motor run.
The blower motor gets power from a 30amp fuse which gets power from a relay.

I'm showing a blower relay and a resistor used on models with manual ac control.
The blower motor is grounded and the fan switch provides power thru the resistor. So you have a 40amp blower fuse that handles high thru the relay, then a 30amp HVAC fuse that powers the blower thru the fan switch.
Do you not have power from the resistor to the blower motor on the purple wire ?

Check this procedure...Blower Motor Resistor and Controller Replacement


REMOVAL

1. Disconnect and isolate the batten' negative cable.

2. Depress locking tab and unplug the wire harness connector from the blower motor

resistor or controller (power module).

3. Depress locking tab and unplug the resistor or controller connector from the blower

motor.

4. Remove the 2 screws that secure the blower motor resistor or controller to the

heater-AC housing.

5. Remove the blower motor resistor or controller from the heater AC housing.


INSTALLATION

1. Install the blower motor resistor or controller to the heater AC housing. The

housing is indexed to allow (controller power module) mounting in only one

position. Tighten the mounting screws to 2.2 Nm(20 in. Lbs.).

2. Plug in the wire harness connector to the blower motor resistor or controller.

3. Plug in the connector from the blower motor resistor or controller to the blower

motor.

4. Connect the batten' negative cable.




Hope this helps (rerember to rating this and leave a testiomonial).

Using a test light, check for power at the blower motor connector. If thereis power there, replace the blower motor. If there is no power there, it could be the blower motor switch or the blower motor resistor. The most common is the blower motor resistor.

Hello hfg.

1. First of all, tap the blower motor gently to see if it starts it. If it does, the brushes or the armature in the motor are worn- replace the motor.
2. If that doesn't help wiggle the connector on the motor and the blower motor resistor. There may be burned or loose connections.
3. If you have power on fuse 7 with the key on, then check for power at the blower motor on the blue white wire. If no power on it you have a break in the wire between the fuse and the blower.
4. Next, check for power on the blue black wire. If there is power there that proves there is continuity through the motor(that's good), if not, replace the motor.
5. The blue black wire then goes to the blower resistor. this resistor gives the different blower speeds.
inside the resistor there is a thermal fuse. It isn't replaceable, only the resistor as an assembly.
If the thermal fuse blows it may indicate that the blower motor is beginning to wear out and draw too many amps. And then you may need to replace both the blower and the resistor.
Check with an ohmmeter across the thermal fuse. If it is open circuit, replace the resistor and the blower. If you don't replace the blower it may blow the new resistor again.
6. If it all checks out to this point, ground the blue/red wire at the resistor. If the blower comes on the problem then becomes the blower switch or a break in the wire to the switch.

Whew.. Hope this helps solve the problem, my fingers are sore..Ha.

Thanks for using FixYa.

KL

Welcome to FIxYa.com

Blower Motor Resistor and Controller Replacement

Image Blower Motor Resistor Or Controller/Power Module Remove/Install

REMOVAL

1. Disconnect and isolate the batten' negative cable.

2. Depress locking tab and unplug the wire harness connector from the blower motor

resistor or controller (power module).

3. Depress locking tab and unplug the resistor or controller connector from the blower

motor.

4. Remove the 2 screws that secure the blower motor resistor or controller to the

heater-AC housing.

5. Remove the blower motor resistor or controller from the heater AC housing.

INSTALLATION

1. Install the blower motor resistor or controller to the heater AC housing. The

housing is indexed to allow (controller power module) mounting in only one

position. Tighten the mounting screws to 2.2 Nm(20 in. Lbs.).

2. Plug in the wire harness connector to the blower motor resistor or controller.

3. Plug in the connector from the blower motor resistor or controller to the blower

motor.

4. Connect the batten' negative cable.

Thank you for using FixYa.com

Regards, Lee Davidian

It will be up under the dash on the passenger side near the blower motor. It will have 5 or six wires in its connector

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Check the blower multispeed control resistor pack is not faulty.
The resistor pack is usually located in the air ducting, in the blower fan airflow.
Basically, +12v power is supplied (via fuse) to the fan speed control switch, which then passes via the selected speed control resistor, to the fan motor. Often a interface relay is used to switch the blower motor high current.