Expert: Chris Fortunato - 4/9/2007

Question
What is wrong is the a/c is blowing cool air but it is not coming out the vents only out from underneathe the dash and out the top of the dash?

Answer
Tina,

Normally, this indicates a fault in the air distribution system. Most are designed to default to 'defrost' mode, which puts most airflow out at the windshield, and a little out the heater vents (under the dash). More specifically, the device that causes this change, when it's functioning properly, is the Mode Door actuator -- this directs flow, from commands on the A/C Control Head (where you control the system). This basically adjusts the mode door position (defrost, panel, heater, etc), and is operated either by engine vacuum or electronically.  

The types of systems vary widely, and some are extremely complex. This condition is very typical of easy fixes like a vacuum leak between the engine and the Control Head rotary valve, but it can also be very difficult -- often requiring the use of a handheld scantool to properly diagnose the A/C system. You'll probably need to take it to a mechanic, unless you have service information for your vehicle, and a willingness to fix it yourself. Good luck!