I have a Kia Sedona 2009 LX with an Air Conditioner problem. When I turn the knob that turns on the AC, most of the time air will not blow on the front. Sometimes it does. Air always does blow in the back and middle of the van however. But the air blown is not cold. When air does blow on the front when the AC knob is turned to the on position, the air blown in the front is very cold, as well as the back and middle of the van. There does not seem to be a pattern as to when turning the front AC knob will result in the AC working or not. Thank you for your help in advance.
There are 31 trouble codes that can give problems to the A/C system so it is hard to give you a proper diagnosis with out a scanner and a Digital volt/ohm meter that can give trouble codes and electrical readings that can lead the mechanic to the area of the problem.
Take your car to the dealer and have them use there factory scanner to check the A/C system. The scanner can check all of the inside cabin sensors, door actuators for temperature and air direction and also check the compressor operation through pressure sensors installed it the A/C pressure hoses and compressor.
If there is malfunction in any of the electrical sensors the scanner will indicate this to the mechanic so he can properly repair the vehicle.
Can you tell me if it's manual or automatic A/C. The automatic A/C has a transistor which controls front blower speed. The PCM monitors blower operation. If the blower
stops, the PCM shuts off the compressor. That would explain the rear A/C getting
warm when the front blower quits. It could be a bad front motor, transistor,
or connection. Also is the blower noisy? The next time the blower shuts off hit the motor to see if it comes back on and does it also work on all speeds?