While driving in the rain one day, with the A/C on, I noticed a lot of cold water under the passenger seat. Under each seat in my car, there is a very flat hose, which I assume is to vent air to the back seat passengers. I thought that the water condensed and leaked out under the passenger seat, but the dealership is totally stumped! They’ve checked everything that seems relevant, including the evaporator coil, but that’s not it. They couldn’t duplicate the problem. They could not find a way to help me and now I have to live with Mildew in my car! Please tell me what to do and how to find help for this problem. Thanks.
If the A/C evaporator drain is clogged or partly clogged, then the water condensation from the normal A/C operation cannot drain out of the evaporator case and has to go somewhere. The place it usually goes is out of is the floor vents. Have the A/C evaporator drain checked and cleaned out. Try to not park under trees that shed the leaves and seeds in the future. This is what clogs the drain. As for the mildew, there are several methods listed in this article for maintaining car upholstery after liquid damage.