That plastic line is most likely the vacuum hose that runs the heater controls. The mode doors are spring-loaded to default to the defrost position for safety. Your feet might freeze but your windshield will be clear.
There's a vacuum hose routing diagram on a sticker under the hood. If that broken hose is cracked, you can splice it with a piece of rubber hose. If it has a rubber fitting on the end, it came off the check valve which will be laying nearby.
Saturday, August 17th, 2013 AT 1:07 PM