When it rains, and the truck is turned off (like in the driveway over nite), I get water dripping down out of the center of the heater vent unit which drips onto the rubber boot of my shifter and then runs around it to run across the carpet. What I'm wondering is might this be a windshield leak somewhere or is there some way that the water is getting in through the HVAC intake system and running in? Is there a weep hole somewhere that might be plugged? Maybe a vacuum actuator that is supposed to close something when the engine is turned off that doesn't? This does not seem to ever happen when the truck is running and I've driven some serious rain this year. Any ideas?

 

I know that several people have had issues with windshield leaks. Sometimes they leak down the drivers side and get into the fuse block.