I have a 2002 F150 SuperCrew with the 5.4L V8. Starting a few months ago I have had a pool of water on both the driver and passenger floor. I have had it in the shop for them to see where the water was coming from and it is from the AC drip pan. The line from the firewall to the drip pan has been blown out a few times with the last one not doing anything.

Now my only option appears to be about $1k to have the dash removed to access the box. At that point I would have the heater core replaced. Is there another option that would either be a quick home repair that would not require removal of the airbag or the entire dash? I was thinking about running a new line from the drip pan to the outside of the truck.

 

I have a 2003 XLT Xtra-cab with the same issue. Here is what I found out and did: When looking under the hood or from under the truck I could see the small hose that comes through the firewall. Getting to it isn't easy so I ended up using a long piece of copper tube attached to my air nozzle and tried to blow air into the box to unblock things. I could never get any water to drip out. After an hour or so working on the issue, I got under the truck once again and I seen water on the ground so I looked at the tube again and didn't see any thing. I was getting frustrated when I noticed a small plastic cover under the hose that I could see and I decided to take it off. All that was holding it was two plastic push-pins. Once the cover was removed, there was another hose just like the one above it but water was dripping from this one. Seems I had been working on the wrong one the whole time. So after checking everything out, I realized that the tube wasn't stopped up and what was happening was the water was coming out of the tube and getting sucked up by the foam that was around it at the firewall and was being transferred back into the floorboard inside. ( I later read where the plastic cover was added to block air coming from the engine compartment from pushing the water back into the tube or back against the firewall. ) Since everything was so tight where this tube was located I just decided to get some silicone and apply a nice thick layer around the tube and exposed foam gasket. The bottom half of the tube and gasket seemed to be the most important area. Well after letting it sit and cure....I now have no more water coming back into the floorboard area. One last thing that I tried before realizing that I was messing around with the wrong tube - I removed the bottom cover from inside of the passenger side, the cover that allows you to replace the cabin filter if you have one, and I drilled a small hole in the face of the air box on the left hand side so I could push a wire inside and exit outside through the tube. I drilled the hole low enough on the face so when I plugged it and replaced the bottom cover, the hole or plug couldn't be seen. I was pushing the wire inside and thought that it was hitting something solid but every time I looked, there wasn't a wire coming out of the tube. Again this was before I removed the plastic cover under the tube that I could see in the engine compartment. The wire was exiting the tube and actually hitting the plastic cover. Anyway, hole plugged, bottom cover put back on, tube - foam gasket covered in silicone, cover installed and everything is fine...... Sorry so long but maybe it will save someone else some time.