If the HVAC (heater) housing is not properly sealed at the bulkhead (firewall), water can leak into the passenger compartment. Foam sealant should be used to seal any gaps and the evaporator drain tube can be modified to prevent further water entry.
Water Leak Due to HVAC Case Not Sealed at Bulkhead on Dodge Caravan
Average mileage: 102,500 (95,000–110,000)
11 people reported this problem
Water from AC leaks onto passenger floor
2000 Dodge Caravan 95,000 mi, Visitor
Water just started too come in on passenger floorboard
2003 Dodge Caravan 110,000 mi, Visitor
Water on floorboard of passenger side noted. Pulled trim and carpet to find puddles and soaked mats. Cleaned evaporator tube for HVAC which may have staved water flow some when A/C running but otherwise, still leaks in some. Plan to put silicone or this "foam sealent" around tube at exterior and as best as one can on interior then add a L shaped tube to the evaporator tube to divert flow groundward rather than allow it to flow back to firewall (bulkhead).
Water leaking into the right front passenger compartment.