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.Google+
Car Problem Reports
Dodge Grand Caravan Water Leak Due to HVAC Case Not Sealed at Bulkhead
Dodge Grand Caravan Problem
Average Mileage: 120,822 mi (50,000 mi - 240,000 mi)
Visitor, 2003 Dodge Grand Caravan, 50,000 mi
any time we use the air conditioner, water leaks onto the floor of the passenger side. carpet is always soaked!
Visitor, 2005 Dodge Grand Caravan, 154,000 mi
HVAC leaks on the passenger side carpet.
Visitor, 2002 Dodge Grand Caravan, 98,000 mi
vehicle is leaking from underneath the passenger side of my 2002 chrysler van. the front passenger floor is always wet.
Visitor, 2001 Dodge Grand Caravan, 118,000 mi
when air conditioner on in summer the passenger side rug and carpet get soaked and has a white residue.
Visitor, 2003 Dodge Grand Caravan, 85,000 mi
Leaks in heavy rain
Visitor, 2001 Dodge Grand Caravan, 138,000 mi
Front passanger side carpeting is always wet.
When the A/C is on there is a leak from the firewall area. My guess is a misalignment of heater core as my dashboard once had to be removed to track down an electrical issue. This problem has not been fixed.