* Blower Motor Resistor: This is the most likely culprit. The resistor is a component that regulates the speed of the blower motor. When it fails, often only the lowest speed setting works because that's usually the only speed that bypasses the resistor. This is a relatively inexpensive and easy part to replace.
* Blower Motor: While less likely than a bad resistor, a failing blower motor can also cause this issue. As the motor brushes wear down, it may lose power at higher speeds. This is a more expensive and involved repair.
* Wiring Issues: Damaged or corroded wiring between the blower motor switch, the resistor, and the motor itself can interrupt the power supply to the higher speed settings. This requires careful inspection and possibly some wiring repair.
* Blower Motor Switch: Less common, but a faulty blower motor switch itself can cause this. It's possible the higher speed contacts are worn or broken.
Troubleshooting Steps:
1. Check the fuses: Make sure all fuses related to the blower motor are intact. This is a simple and quick first step.
2. Inspect the blower motor resistor: Locate the resistor (usually behind the glove box or under the dash) and visually inspect it. Look for any signs of burning, melting, or obvious damage. This often requires some disassembly.
3. Test the blower motor resistor (if accessible): Some resistors can be tested with a multimeter to check for continuity. However, this requires some electrical knowledge.
4. Test the blower motor: This is more complex and often requires removing the blower motor. It involves checking the motor's windings for continuity and testing its resistance. Again, this requires electrical knowledge and tools.
5. Check the wiring: Look for any frayed, melted, or disconnected wires in the blower motor circuit.
Recommendation:
If you're not comfortable working on electrical systems, it's best to take your Savana to a qualified mechanic. The blower motor resistor is a common and relatively inexpensive fix, and a mechanic can quickly diagnose the problem. Replacing it yourself is usually straightforward, but accessing it can vary depending on the year and model of your van. Consult a repair manual or online resources specific to your Savana's year and model for detailed instructions.
