1. Identify the Source:
* Check the AC Drain: The most common culprit is a clogged drain line that runs from the evaporator core (located behind the dashboard) to outside the vehicle. This drain carries condensation from the air conditioning system. A blockage causes water to overflow and drip onto the passenger floor.
* Location: You'll likely need to look under the dashboard on the passenger side. The drain is usually a small tube or hose. It's often difficult to access; you might need to remove some trim pieces. A shop manual for your specific year and model Cherokee will be very helpful in locating it.
* Inspection: Once you locate it, check for any visible clogs (leaves, debris, etc.). Try using a long, thin, flexible object like a coat hanger or a shop vacuum with a narrow attachment to clear any blockage.
* Check the Heater Core: While less common, a leak in the heater core can also cause wetness, especially if it’s only present when the heater is on. This is a more significant repair, requiring potentially removing the dashboard.
* Sunroof Drain (if equipped): If your Cherokee has a sunroof, clogged sunroof drains can sometimes lead to water pooling and potentially finding its way to the passenger side. Check the drain tubes around the sunroof frame for clogs.
* Exterior Seals and Weatherstripping: Inspect the exterior seals around the windshield, doors, and windows on the passenger side for any gaps or damage that might allow water to enter.
2. Repairing the AC Drain (most likely solution):
* Clear the blockage: Once located, use compressed air or a shop vac to clear the drain line. Pouring a solution of water and baking soda (a mild cleaning agent) can help flush out debris. You may have to repeat this process a couple of times.
* Replace the Drain Line (if damaged): If the drain line is cracked, damaged, or disconnected, you'll need to replace it. This usually requires some disassembly of the interior, so again, a shop manual is highly recommended. You might find a replacement drain tube at a parts store or online.
* Improve drainage: After clearing the blockage, consider periodically using compressed air to prevent future clogging.
3. Other Potential Leaks:
* Windshield Seal: A leaky windshield seal is another possibility. This would require a windshield replacement or sealant repair.
* Floor Well Drain: Check for proper drainage of the floor wells outside the vehicle. If leaves, dirt, or other debris is blocking these, remove it.
4. When to Seek Professional Help:
* If you can't locate the drain: Accessing the AC drain can be challenging. A professional mechanic will have the expertise and tools to locate and repair the issue efficiently.
* If you're uncomfortable working on your vehicle's HVAC system: This is a complex system, and improper repairs can create further problems.
* If the leak persists after attempting the above steps: It could indicate a more serious problem requiring professional diagnosis.
Important Notes:
* Safety First: Always disconnect the negative battery terminal before working on any electrical components in your vehicle.
* Shop Manual: A repair manual specific to your 2000 Jeep Cherokee will be invaluable. It provides diagrams, instructions, and torque specifications, making the process safer and more efficient.
* Patience: Locating and fixing the leak may take some time and persistence.
If you're not comfortable working on your vehicle yourself, take it to a qualified mechanic for diagnosis and repair. A properly diagnosed and repaired leak will prevent potential mold growth and damage to your vehicle's interior.
