Automobile air conditioning systems that emit heat on one side and cold on the other typically have one of two problems. In this short article on auto repair, a master auto technician shares his experience, derived from working on air conditioners in Florida for the past two decades. This free information can be just as useful to the DIYer as it is to a consumer who knows the value of being informed when it comes to dealing with auto repair shops. Read on for free car air conditioning help when the air is blowing hot on ONE side.

Cars that blow cold on one side of the dash and heat on the other are typically equipped with a dual-zone climate control system. Dual zone systems allow the driver and front passenger to adjust respective temperatures to their comfort levels. There are two common causes of a temperature difference when both sides are set to the coldest setting, let’s cover the first one.

low coolant

Car air conditioners using 134A generally contain a small amount of refrigerant compared to older cars using R12. Today’s car and truck air conditioners are much more efficient than their older counterparts. The fact that 134A systems use less freon means that a leak can more quickly affect the performance of an HVAC (heating, ventilation, and air conditioning) system. Due to the design of dual AC systems, low coolant is the primary cause of the drastic temperature difference from one side of the switchgear to the other. Even highly experienced auto mechanics may be surprised to learn that as little as 4 to 8 ounces of 134A at no load can make a world of difference. The temperature from the left to the right vent can vary from 10 to 20 degrees. The easiest thing to try is to recharge the system or, better yet, flush out all the freon and recharge the unit with the factory-specified amount. In most cases, after the proper charge of Freon is in the car, the temperature will drop just as cold as it should on BOTH sides!

What if that doesn’t help? Read on for another possible cause of the problem.

HVAC door problem

Dual zones supplying different temperatures from vents on each side of the dash are achieved through the use of small doors within the HVAC housing. By controlling the doors, the air temperature on the left and right can be adjusted to the desired comfort level. Many times, the motor (or actuator) that controls the door on either side can fail or the door itself can break and avoid temperature. to be adjusted. Diagnosing this problem is more complex and may be the subject of another article. Thank you for reading. Hopefully, the free information provided here will help remedy the “air conditioner blowing hot or warm from the side of the dash” problem.