* Blower Motor Resistor: This is a common culprit. The resistor controls the fan speeds. If it fails, the blower might only work on high speed (if at all), or not at all. A faulty resistor often results in burning smells.
* Blower Motor itself: The motor could be failing due to wear and tear, brushes wearing down, or internal shorts. This often results in a complete lack of fan function, or intermittent operation.
* Fuse: A blown fuse in the blower motor circuit will prevent it from working. Check your owner's manual to locate the correct fuse.
* Relay: The blower motor relay acts as a switch. A bad relay can prevent power from reaching the motor.
* Wiring Issues: Damaged, corroded, or loose wiring in the blower motor circuit can interrupt power. This could be anywhere from the fuse box to the motor itself.
* Control Module (HVAC Module): This is the "brain" of the climate control system. A faulty HVAC module can cause a variety of problems, including the blower motor not working. This is usually a more expensive repair.
* Low Voltage: Sometimes insufficient power reaching the blower motor due to other electrical issues in the car can prevent proper function. A failing alternator, for instance, could be a contributing factor.
* Switch Issues: Though less common, a faulty blower motor switch itself can prevent the fan from turning on.
Troubleshooting Steps:
1. Check the fuses: This is the easiest and cheapest first step.
2. Inspect the blower motor resistor: This often involves locating it behind the glove compartment or under the dashboard.
3. Check for obvious wiring problems: Look for any frayed, broken, or corroded wires.
4. Test the blower motor relay: This might involve using a multimeter to check for continuity.
5. Listen for clicking sounds: Clicking sounds can often indicate relay problems.
6. Check the blower motor itself: This is generally done by testing with a multimeter to see if it receives power and if it functions when power is applied directly (Caution: Only attempt this if you have experience with automotive electrical systems. Incorrectly handling the motor or its wiring can cause injury or damage).
If you're not comfortable tackling electrical repairs yourself, it's best to take your Impala to a qualified mechanic for diagnosis and repair. They have the tools and expertise to properly diagnose the issue and safely repair it.
