1. Preparation:
* Consult a repair manual: A factory service manual or a Chilton's/Haynes manual specific to your 1986 GMC Suburban is *crucial*. These manuals provide detailed diagrams and instructions specific to your vehicle's year and model. This will save you significant time and frustration.
* Gather tools: You'll likely need a variety of screwdrivers (Phillips and flathead), possibly sockets and wrenches (sizes will vary), pliers, and possibly a trim removal tool to avoid scratching the dash.
* Prepare workspace: Work in a well-lit area. Consider using a shop rag or towels to protect the dash and surrounding areas from scratches.
2. Accessing the Blower Motor:
This is the most challenging part, as access varies considerably. Generally, you'll need to:
* Remove the glove box: This usually involves removing screws and possibly some clips.
* Remove parts of the dashboard: This is where your repair manual will be indispensable. You may need to remove the radio, trim pieces, and possibly even parts of the center console to gain access to the blower motor housing. The amount of disassembly will depend on your truck's configuration. Take pictures as you go to aid in reassembly.
* Locate the blower motor: It's usually located behind the dashboard, often near the passenger side.
3. Removing the Blower Motor:
* Disconnect electrical connectors: Carefully unplug the wiring harness connected to the blower motor. Take a picture or make a note of how the wires are connected to prevent confusion during reassembly.
* Disconnect the blower motor: This usually involves removing screws or bolts holding the motor in place. Again, your repair manual will show you the precise location and type of fasteners.
* Remove the blower motor: Once the fasteners are removed, carefully pull the blower motor out of its housing. Be aware of any ducting or other components that might be attached.
4. Installing the New Blower Motor:
* Install the new blower motor: Carefully insert the new blower motor into its housing, ensuring it's properly seated.
* Reconnect the blower motor: Secure the motor with the screws or bolts.
* Reconnect the electrical connectors: Plug the wiring harness back into the blower motor, ensuring all connections are secure.
* Reassemble the dashboard: Carefully reassemble all the components you removed, referring to your pictures or the repair manual.
5. Testing:
* Reconnect the negative battery terminal.
* Turn on the ignition and test the heater/AC system: Check all blower speeds to ensure the new motor is working correctly.
Important Considerations:
* A/C systems: If your Suburban has air conditioning, the process might be more complex due to additional components.
* Resistance: The new blower motor should have the correct resistance to match the original. Check the specifications of your old motor to ensure you buy a suitable replacement.
* Professional help: If you're uncomfortable working on your vehicle's dashboard or unsure about any step, it's best to consult a qualified mechanic. Improper disassembly or reassembly can lead to damage to your vehicle's interior.
This is a general guide. The specific steps and difficulty will vary based on your Suburban's configuration. A repair manual is absolutely essential for this repair. Don't attempt this without one.
