Blower motor resistor replacement

The relay in your blower motor is stuck on, there is a TSB for this issue. Replace the blower motor resistor and you'll be back in business.
How does the resistor get power if the fuse is pulled?
Replacing the resistor will cure both problems. TSB is a technical service bullitin seen below
Subject:HVAC Blower Motor May Run Continuously After Vehicle is Turned Off (Replace Blower Resistor Relay)Models:2004 Chevrolet Avalanche, Silverado, Suburban, Tahoe, TrailBlazer, TrailBlazer EXT2004 GMC Envoy, Envoy XL, Sierra, Yukon, Yukon XLwith Manual Control HVAC (RPO CJ3)Built Prior to August, 2003

In the beginning you should check for voltage and ground.
The 50amp fuse marked AC powers the blower motor and the motor is grounded.
The high speed relay bypasses the resistor. So you should have power coming from the fuse and thru the high relay. Then the resistor for the other speeds gets power from the heat and ac control module which also controls the blend doors.
You may need a shop manual or repair book to get the diagrams.

Blower motor resistor block is attached with two screws opposite side of the blower motor

Your truck may have a bad blower motor resistor. It can be very easy to replace, if you have a "work truck" or plain truck just look under the dash and you can see it, it has a connector with about 6 wires on it, it is right beside the blower motor. If you have a higher end truck like a LT or Z71 you will need to remove a plastic trim panel to see it, this will be difficult if you have a center console. You may also have a bad blower, to test this you will need to disconnect the two wire connector on the motor when the fan stops working and check for voltage on the red wire. If there is no power then the resistor is bad, if there is you have a bad blower. But you will need the problem to act up to properly test this.

You need to replace the blower resistor assy. it is located down by the blower motor on the passenger side near the passengers feet. it will be held in by 3 screws. you should also check the connector for the wiring that goes to it as they have a tendency of melting. The wiring harness is available at the dealer. Purchase the resistor at the dealer and they can print off a picture of its location and or verbaly explain where it is. good luck

They are there. They are hard to get to. What is the complaint? Have you checked the fuse? Blower fuse (50 amp) under the hood.HTR-AC fuse (25 amp) in the instrument panel fuse box

hello,good day,first try to check your blower switch,if not corrected,your blower resistor is located at the bottom of your brake booster,ty

There is an updated resistor/connector package. Very expensive from GM, try your local NAPA or other parts supplier for a replacement

yes you have to take out the dash and the glove box to get it out. its on the passenger site in a black plastic housing.

You need to replace the blower motor resistor