Here's a breakdown of how to troubleshoot:
1. Check the Resistor Pack:
* Location: The resistor pack is usually located behind the glove box or under the dashboard, often near the blower motor itself. You'll likely need to remove the glove box or some interior trim panels to access it. Consult a repair manual or online resources specific to your year and model Caravan for the exact location.
* Inspection: Once located, visually inspect the resistor pack for any obvious signs of damage, such as burning, melting, or loose connections. Sometimes, you can even see a broken resistor element.
* Testing (Advanced): If you have a multimeter, you can test the resistance of each resistor element within the pack to see if they're functioning correctly. However, this requires some electrical knowledge and is not necessary for a basic diagnosis.
2. Check the Wiring:
* Visual Inspection: Examine the wiring harness connected to the resistor pack for any signs of damage, such as frayed wires, loose connections, or corrosion.
* Continuity Test (Advanced): A multimeter can be used to test the continuity of the wires leading to and from the resistor pack to ensure there are no breaks in the circuit.
3. Check the Blower Motor (Less Likely):
While less likely to be the cause if high speed works, a failing blower motor *could* cause issues with lower speeds. A completely failing blower motor would likely mean no fan at all, though.
4. Fuse Check (Rare): While uncommon to affect only certain speeds, a blown fuse *could* be a culprit. Check your vehicle's fuse box for any blown fuses related to the heater blower motor.
What to do next:
* Replace the Resistor Pack: If you find any damage to the resistor pack or its wiring, replacing it is the most likely solution. These are relatively inexpensive and readily available online or at auto parts stores.
* Professional Help: If you're uncomfortable working on your vehicle's electrical system, it's best to take it to a qualified mechanic.
Important Note: Always disconnect the negative battery terminal before working on any electrical components in your vehicle to prevent accidental short circuits. Consult a repair manual specific to your 2002 Dodge Caravan for detailed instructions and diagrams.
