1. Check the Fuses and Relays:
* Locate the fuse box(es): Your Silverado likely has an underhood fuse box and possibly one inside the cabin (often under the dash). Consult your owner's manual for the exact locations and fuse/relay diagrams.
* Check the blower motor fuse: Look for a fuse labeled "blower motor," "HVAC," or something similar. Replace it if it's blown.
* Check the blower motor relay: This is a small electrical switch. You might need to swap it with a known good relay of the same amperage rating to test it. (Again, your owner's manual is crucial here).
2. Check the Blower Motor Resistor:
* Location: The blower motor resistor is a common failure point. It's usually located behind the glove box or under the dash, often clipped to the HVAC housing. Its purpose is to control fan speed. A faulty resistor can cause the blower to not work at all or only work on high speed.
* Testing: You can visually inspect it for burned components or measure its resistance (ohm) with a multimeter if you have one. Many online resources offer guidance on testing this resistor for your specific model year.
3. Check the Blower Motor Switch:
* Testing: This is the switch you use to control fan speed. A faulty switch can prevent power from reaching the motor. Testing this requires more advanced tools and knowledge of automotive electrical systems. It's often easier and cheaper to replace the switch than to diagnose the problem.
4. Check the Blower Motor itself:
* Accessibility: This is typically located behind the dashboard, requiring partial disassembly to access.
* Testing: You can test the motor for continuity with a multimeter. If it's faulty, it needs replacement. However, this is usually the last thing to suspect, as the issues above are more common. You'll want to ensure power is reaching the motor before condemning it.
5. Wiring and Connections:
* Inspect: Check all wiring and connectors related to the blower motor, resistor, and switch for loose connections, corrosion, or broken wires.
Before you start:
* Consult your owner's manual: This is your best resource for fuse box diagrams, relay locations, and troubleshooting tips specific to your vehicle.
* Disconnect the negative battery terminal: This is a crucial safety precaution before working on any electrical components.
* Gather tools: You'll likely need screwdrivers, possibly a multimeter, and replacement parts.
If you're not comfortable working on car electrical systems: It's best to take your Silverado to a qualified mechanic. Incorrect diagnosis or repair could lead to further damage. The cost of professional diagnosis is often far less than the cost of replacing multiple parts unnecessarily.
