Thanks for this. I'm having the same problem, leaking on driver's side and passenger floorboards. Coming from under dash center. I've sprayed air up into the drain as described here twice now. It wasnt dripping out before but now it is. However, it's still leaking inside the cab. If I run the ac for 5 mins and then shut off the truck, water will puddle on the ground as it should. But still leaks from under dash. We've had no rain for a couple weeks, so it's definitely coming from the AC. Where/what else should I check. Thanks guys.