I have a 96 tahoe, 2dr sport and the pass floor was coninuously wet after it rained. I took it to a mechanic friend of mine and he said they removed the cowel and there was something inside there to do with the heat/ac and it was actually funneling the water into the blower box. The water then drained onto the carpet. He cut something out of the way and siliconed the crap out of it. No problems since and its been about 6mos. Sorry I can't be more informative but its a start.