A/C drip tube?

If your truck is high enough look underneath it were the evap plenum meets the firewall, you should see a hole in that area, clean it with a plastic tie wrap so you don't punture anything in the case!

Open the hood, look were the A/C lines go into the truck, that's the plenum!

Well if you go to an A/C -plumbing supply house, you can buy evaperator core wash, this will not harm the metal it's made of, then pour some into the air intake with the fan on high, this will flush the gunk out of the core! Air intake is accessed by removeing the wiper blades on some models, then take off the cowl then you should see the air intake, you may have a cabin air filter, remove it first to see the intake. Pour this SLOWLEY! It must pass by the electric fan! Option 2 get some compressed air in a can, use the plastic extension and blow the clog out.

According to Dodge the intake is under that cowl. Look for any grilled ir finned area under there. You can blow up into it.