05 Chevy Cobalt with 180k. It’s started dripping water onto the passenger side floor. I found the drain for it. I put 100 psi of air and 2+ feet of a drain unclogging tool up it but still having the same problem. When I blasted the air up it, it actually backed up a few more drops of water into the cabin. It seems like the drain splits into two channels inside of it and I’ve tried them both. Any other ideas?
You may have made things worse with your overly enthusiastic methods. The usual advice is to use string trimmer line to get to the clog without damaging the tubing or the evaporator.
You need to suck the debris out of the drain tube, not blow it back into the A/C case. You probably made things worse.
If you can’t get the drain hole free from the outside you may need to remove the case from the inside of the car and clean it out.