Is there an overflow tube, which may be blocked for the blower/air intake like on our old 2001 Grand Prix..?? Everything still works well on the '99 Tahoe, but the water baffles me.. Anyone??
It could be blocked but it won't fix the issue. On that body style of trucks there is a screw that holds the black cowl trim down between windshield and hood. This screw is right above the air intake for the HVAC system. It's the second screw in from the passenger side.
Remove it, put some rtv on the threads and replace it. Enjoy dry floors!
I actually removed ALL the screws and did a good sealant before replacing the screws.. Helped some, but not totally..
Will recheck the one noted just to be sure..
Bought my Tahoe new in 1999.... Going to hit 100,000 this weekend..!!