Heater fan does not shut off

Good morning,

There is a blower motor resistor that controls fan speed. When it shorts to power, this is the result.

It is next to the blower motor under the right side of the dash. I attached a picture and wire diagram for you to view.

Roy

This might help, Subject: Blower Motor Inoperative or May Not Shut Off in Extremely Low Ambient Temperature Conditions (Replace Blower Motor Control Module)

Models: 2004-2007 Buick Rainier

2003-2006 Cadillac Escalade Models

2003-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2003-2007 Chevrolet TrailBlazer Models

2007 Chevrolet Silverado (Classic)

2003-2006 GMC Sierra Models, Yukon Models

2003-2007 GMC Envoy Models

2007 GMC Sierra (Classic)

2003-2004 Oldsmobile Bravada

2003-2006 HUMMER H2 Models

with Automatic Temperature Control HVAC System (RPO CJ2) Some customers may comment that the blower motor is inoperative or continues to run after the vehicle has been shut off. These conditions may be caused by a blower motor control module failure. This failure may occur when the vehicle is operated in ambient temperature conditions of -23 °C (-10 °F) or below. Important: Replace the blower motor control module if the vehicle experienced a blower motor control module failure in extremely cold ambient temperature conditions. Technicians are to replace the blower motor control module, also called the Linear Power Module (LPM), After replacement of the blower motor control module, the customer may notice a slightly higher than expected blower motor speed at any of the blower speed settings.

Replace the blower motor resistor and connector, this is a very common problem. Post back with any other questions.

Its on the pass side under the dash, there is a sheild under it, take it off and its wright there.

Is this an auto temp control system with an automatic fan speed?

Then you most likely have a bad blower speed control module. It's located under the dash, right next to the blower motor.