If it only does this after a rain, chances are you have a leaking windshield. Or the aircond. drain is clogged, even if you are only using the defrost with heat the air-cond. runs with the defrost.
you left the windows down while it was raining
I hav e the same problem
what is it leaking? water, oil,coolant,or gas
The AC drain on a 2002 Dodge Grand Caravan EX is located underneath the front of the vehicle. Often, when the drain is clogged, water will leak into your vehicle and get the floorboards wet.
Remove it with a wet/dry vac.
heater core is shot...
3.1 engine leaks at the intake gasket
I had this problem, the weather stripping had come loose. Try removing the water deflector (underneath the wipers). If the weather stripping is loose, put it back into place with some black epoxy.
If you have leaks in a water bottle rocket, the pressure will quickly escape along with the water and the rocket won't be able to reach as high an altitude as a rocket without leaks.
if it rear air and heat it could be the line carring the antifreeze tho the back heater core.
you need to replace your heater core.
Most likely your heater core has gone bad.