Here's a general outline of the process. Specific wire colors and locations may vary slightly, so consult your Avalanche's wiring diagram or a reputable wiring guide specifically for your year and model. You can often find these online through forums dedicated to Avalanche owners or from repair manual providers like Haynes or Chilton.
1. Choose a Brake Controller Location:
* Select a location within the vehicle where the controller will be easily accessible and visible to the driver but also secure and protected from damage.
2. Identify the Wiring Harness:
* Locate the 7-way or 4-way trailer connector: This is typically located on the rear of the vehicle. The 7-way is more common and provides power to the trailer lights and brakes.
* Find the power source: You'll need a switched 12V power source (one that only turns on when the ignition is on) for the controller. This could be found in the fuse box or by tapping into a suitable wire under the dash. Consult your vehicle's wiring diagram to identify a suitable source.
* Ground Wire: Locate a clean, unpainted metal surface on the vehicle's chassis for a solid ground connection.
3. Run the Wiring:
* Carefully route the wiring harness from the brake controller to the 7/4-way connector at the rear of the vehicle, trying to avoid sharp edges or moving parts. You may need to use grommets or other protective measures to keep the wiring from being damaged.
* Consider using a relay: Depending on the brake controller's amperage rating, you might need a relay to protect the vehicle's wiring from overheating. This is especially important if you are drawing power for the controller from a low-amperage circuit.
4. Connect the Wiring:
* Power Wire: Connect the positive (+) power wire from the controller to your chosen switched 12V power source.
* Ground Wire: Securely connect the ground wire (-) to the chassis ground.
* Brake Output Wire: Connect the brake output wire from the controller to the corresponding wire on the 7-way/4-way connector. This is critically important and must be connected correctly. Incorrect connection can result in improper braking or damage. Again, refer to your vehicle's wiring diagram.
* Parking Light Wire (if using a 7-way): Connect this wire accordingly.
* Tail Light Wires (if using a 7-way): Connect these wires accordingly.
* Turn Signal Wires (if using a 7-way): Connect these wires accordingly.
5. Install the Brake Controller:
* Securely mount the brake controller in its chosen location.
6. Test the Installation:
* Connect a trailer to the 7-way/4-way connector. Test all the trailer lights and the braking system. Start with the lights, then very carefully test the brakes at low speed in a safe, controlled environment.
7. Consult the Brake Controller's Manual:
* The brake controller's installation manual should provide specific instructions and wiring diagrams for your particular model. Always follow the manufacturer's instructions.
Disclaimer: This information is for guidance only. Incorrect wiring can lead to damage or injury. If you're uncertain about any step, seek professional help from a qualified automotive technician. Always prioritize safety when working with your vehicle's electrical system.
