I have a 1996 F150. The air conditioner works but I don't see any condensation dripping under the truck. I also hear water sloshing from somewhere in the passenger dash area. This leads me to believe the ac drain is clogged. Does anyone know where the drain is located and how to get to it to unclog it?
Thanks

 

Under the heater box outside the cab

 

On the passenger side on the firewall, you will see the blower motor. Just past that towards the center of the truck is the evap coil where your refrigerant lines will be going to inside of the coil box. The drain is under that coil coming out of that box to a hose. On my 95, it drips on the passenger frame rail almost right where the front door seam is. You can find the hose that comes down off of the drain and either try to suck the clog out with a shop vac, or blow the clog in with some compressed air, but there is a chance it will clog again.

They make foaming cleaners that you can shoot into that hose that will go all the way up and foam up around the coil to clean it. Then it should all rinse out of the drain when you run the AC again.

This video help see how the drain works too:

 

I crawled under the truck on the passenger side and found the drain where bigredtruck said it would be. I used a piece of weedeater line to clean it out. It didn't seem bad. I will pay attention the next time I drive it.