Wet carpeting can mean plugged drain tube

By Doug McAllister

We have seen a few cars come in the shop lately with water on the front passenger-side floor. It is actually not uncommon to see this in the beginning of air conditioning season.

What tends to happen is the condensate drain on the evaporator box gets all plugged up with debris. Instead of the condensation running out on the ground like it's supposed to, the water backs up into the car.

The fix is generally fairly simple. Once you locate the drain tube, typically with a rubber "duckbill" check valve down low on the passenger side of the firewall, you can clean all the stuff that's stuck in it. Once you do this all the backed up water will flow out and things should get back to normal.

Be sure to suck as much water out of the carpet as you can with a wet/dry vacuum. Make sure the carpet fully dries before reinstalling any floor mats.

• Send questions to underthehood@dailyherald.com. Douglas Automotive is at 417 W. Main St., Barrington; 123 Virginia Road, Crystal Lake; and 416 Northwest Hwy., Fox River Grove. For information, visit douglasautomotive.com.