A question regarding my car blowing intermittently hot and cold air.

ANSWER : It sounds like you have failed cooling fans. When the car is at idle, the fans should run to pull air across the A/C condenser to regulate refrigerant temperatures and the radiator to regulate coolant temperature. If these fans fail, then these components will receive no airflow at idle, but will still get airflow while driving due to the car moving. I would suggest having a qualified technician, such as one from YourMechanic, inspect your fan operation, as well as the rest of the cooling system for proper operation.

ANSWER : It is possible that you have a leak in the AC system. There are pressure switches that will turn off the compressor if the pressure is too high or too low. The low refrigerant level could cause the AC compressor to cycle on and off. If you would like to have this done, a certified technician from YourMechanic can come to your car’s location to diagnose the AC system and make the correct repair.

ANSWER : First, the coolant level should be checked to make sure the radiator is full. While the overflow tank may be full, the radiator cap must be taken off to check the level inside the radiator. If you find the level is very low, you have a coolant leak that must be fixed. If coolant levels are normal, an engine thermostat or heater control problem may be what you’re experiencing. Consider hiring an experienced technician like one from YourMechanic who can come out and take a closer look at your lack of heat concern to offer a more personal diagnosis.

ANSWER : Hey there. You will most likely have to have a mechanic bypass the heater coolant lines to have this resolved. Your A/C may not be controlling the air flow inside the evaporator correctly out of the vents and may be the blend door actuator stuck in the heat position. Have the AC system diagnosed first before bypassing the heater.

ANSWER : Hi there. Based on your question and input, it looks like your AC control switches are damaged, causing the vents to activate even if the switch is not activated. This is sometimes an electrical problem, as it could be triggered by a damaged electrical relay. You might want to have a professional mechanic complete an AC is not working inspection, so they can determine what is causing this issue you’re experiencing and recommend the right repair.

ANSWER : The answer to this depends on whether you have switched on heating, cooling (A/C) or neither. In one scenario, for example, if you have not switched on the A/C system, but the A/C is running as confirmed by a visual check of the A/C compressor, and you are getting cool air obviously there is an electrical problem. The coincidental heating could be due to a blend door malfunction. If the only thing you did was remove electrical or electronic components, it would appear that you have an electrical malfunction in the controls. I recommend you request an HVAC diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hello. With the recent repairs that have been made to the vehicle, there is only one main heating component that you have not looked into. This would be your heater core. The heater core is responsible for pulling hot coolant from the engine. This hot coolant runs through the heater core as the ambient air is pushed through to warm before entering the cabin. If the coolant can’t flow through the heater core, then the air will blow cold. This can be caused by a clog, a faulty switch, or a process known as electrolysis (electrical current running through coolant). Unless there is a clog that can be dislodged, these issues will all result in a new heater core. To get a precise diagnosis of the problem, I recommend having an expert inspect the overheating problem so this can be resolved.

ANSWER : Hello. The most likely cause of the issue that your are having would be a faulty cooling fan. The cooling fans purpose is to keep the radiator and condenser for the air conditioning cool during the idling function of the vehicle.

If the cooling fan is not working, this will cause the radiator and condenser to get very hot. When the radiator and condenser get hot, this can cause the vehicle to overheat and the air conditioning not to work. When the vehicle is driving at higher speeds, the force of air that is created towards the vehicle will flow through the radiator and condenser and therefore keep them cool. I would recommend having the cooling fan checked to make sure that it is working properly. If not, I would recommend having the cooling fan replaced.