1. Check the Blower Motor Resistor:
* Location: The resistor is usually located under the dashboard, near the blower motor. It might be behind a panel, requiring some disassembly. Consult a repair manual or online resources (like YouTube videos specific to your van year and model) for the precise location. The resistor is often a small, rectangular or cylindrical component with multiple wires connected.
* How it works: The resistor regulates the voltage going to the blower motor, providing different speeds. A faulty resistor can prevent the high-speed setting from working correctly.
* Testing: Visually inspect the resistor for any obvious signs of damage (burn marks, melted plastic). You can also test its resistance using a multimeter (if you have one) by comparing the resistance values to the specifications in a repair manual. A completely burned-out resistor will often show an open circuit (infinite resistance) on the high-speed connection.
* Replacement: Replacing the blower motor resistor is relatively inexpensive and usually straightforward. You can find replacements at auto parts stores or online.
2. Check the Blower Motor:
* Less likely cause: While less common, a failing blower motor itself *could* cause this issue. If the resistor checks out fine, this becomes a more likely suspect.
* Testing: This requires accessing the blower motor (usually involves removing parts of the dashboard). You'll need to check the motor's windings for continuity using a multimeter. You can also try applying 12V directly to the motor (carefully!) to see if it runs. This is a more advanced test and should only be attempted if you're comfortable working with car electrical systems.
* Replacement: Replacing the blower motor is more labor-intensive than replacing the resistor.
3. Check the Wiring and Connections:
* Inspect visually: Look for any loose, corroded, or broken wires in the wiring harness leading to the blower motor resistor and the blower motor itself. Pay close attention to the connections.
* Test with a multimeter: You can use a multimeter to test the voltage at the blower motor resistor and the blower motor itself at different speed settings to confirm that power is reaching the components.
4. Consult a Repair Manual:
A repair manual specific to your 2000 Dodge Ram Van will provide detailed diagrams and instructions for locating and testing the components involved. This is highly recommended before undertaking any disassembly or testing.
In short: Start with the blower motor resistor. It's the most likely culprit and the easiest to replace. If that's not the problem, then move on to checking the blower motor and wiring. If you're not comfortable with electrical work, it's best to take your van to a qualified mechanic.
