1. Locate the Blower Motor Resistor Pack:
* Under the Dash: This is the most common location. You'll likely need to remove some trim pieces under the dash to access it. Consult a repair manual for your specific Silverado model (a Haynes or Chilton manual, or an online service manual) for precise locations. It's usually a relatively small, rectangular component often attached to the blower motor housing or nearby.
* In the HVAC Housing: Sometimes, it's mounted within the main HVAC (Heating, Ventilation, and Air Conditioning) housing, requiring more extensive disassembly to reach.
2. Inspect the Resistor Pack:
Once you locate it, visually inspect it for:
* Obvious physical damage: Look for burned components, melted plastic, or loose wires.
* Loose connections: Check all wiring connections for corrosion or looseness. Wiggle the wires gently.
3. Test the Resistor Pack (Optional but Recommended):
If you have a multimeter, you can test the resistor pack's continuity. This involves testing the resistance between different terminals of the pack. However, the resistance values are not always straightforward and a schematic diagram (found in a repair manual) would be invaluable. Without it, visual inspection is often more practical.
4. Repair or Replacement:
* Repair (Less Likely to Succeed): If you find a loose connection or a minor visual issue, you might be able to repair it by resoldering connections or replacing a damaged component. This is generally NOT recommended unless you have significant electronics repair experience.
* Replacement (Most Common Solution): It's far easier and more reliable to simply replace the entire resistor pack. This is an inexpensive part readily available from auto parts stores (online and brick-and-mortar). Be sure to get the correct part number for your specific year and model Silverado.
5. Installation:
After getting the new resistor pack, follow these steps:
* Disconnect the battery: This is crucial to prevent electrical shorts and damage.
* Carefully remove the old resistor pack: Take photos or make notes as you disconnect wires to ensure you connect the new one correctly.
* Install the new resistor pack: Connect the wires exactly as the old one was connected. Again, photos are your friend.
* Reconnect the battery:
* Test the blower motor: Turn on the ignition and test all blower speeds.
Important Considerations:
* Repair Manual: A repair manual is highly recommended. It will provide detailed diagrams and instructions for accessing the resistor pack, making the process significantly easier and less frustrating.
* Safety: Working under the dashboard can be awkward. Take your time, work in a well-lit area, and be mindful of any sharp edges or wires.
* Professional Help: If you're not comfortable working on your vehicle's electrical system, consider taking it to a qualified mechanic.
Replacing the resistor pack is usually the solution to this problem. However, if *all* speeds are failing, then the problem could lie with the blower motor itself or a blown fuse. Always check the fuses first before diving into more complex repairs.
