had this issue. The issue for me was a pinch in the drain tube. Before I discovered the issue, I wasn’t able to clear the tube using compressed air or a few attempts to physically clear it using wire, an electrician’s glow stick and even a homemade mini drain snake using a bicycle brake wire and sheath hooked up to a drill- frustrating! Then, I popped off the A-pillar trim and noticed the tube was kinked about where the dashboard and the A-pillar met. I jimmy-rigged a sleeve to go around the tube at the pinched section by cutting about an inch of copper pipe (e.g., the pipe used in home plumbing) and then cutting it one side using a dremil tool. I then used a snap ring tool to expand the sleeve enough to put it around the tube, then squeezed it into shape with pliers. This caused the kink in the tube to return to perfect round shape, thus fixing the issue. Air and water passed through the tube no problem. I learned during the process that the tube dumps the water through the firewall and the outlet is visible (at least on the passenger side) with the hood up. It was a pain to figure all of this out, but with this knowledge I think it would be a very quick repair- hopefully this benefits someone!