Every car has a thermostat on the engine. The thermostat controls the flow of coolant to the engine. It’s a temperature-controlled valve that allows coolant to flow into the motor when it needs to be cooled, but restricts the flow when it doesn’t. This maintains an optimal engine temperature between 180 and 220 degrees Fahrenheit, where the engine is most efficient. The thermostat in your car works in exactly this way, regardless if you have air conditioning or not. Without a thermostat in place, your car would take forever to warm up and reach proper operating temperature, and could overheat easily while driving causing serious damage.
AC thermostats are more common in newer cars.
Most modern cars have AC thermostats, but if you’re driving a car that’s older than five years, it may not have one. The reason for this is the way some automotive AC systems are designed. In these cases, a thermostat is redundant because the system knows exactly how much refrigerant to circulate based on outside temperature and other factors—it can then control the compressor without a thermostat.
If you’re shopping for an AC thermostat or looking to replace yours, be sure to choose one that’s compatible with your car model and its specific AC system.
If a car AC system does not have a temperature sensor, the AC compressor is controlled by an ambient air temperature sensor.
The car AC compressor controls the flow of refrigerant in the system. It will turn on when you press the AC button on your dashboard, and it will stop turning when you turn off the AC.
If a car AC system does not have a temperature sensor, the AC compressor is controlled by an ambient air temperature sensor. This means that if it is hot outside, the compressor needs to run for longer to cool your cabin down to a comfortable level.
An air conditioning thermostat can malfunction due to a faulty evaporator sensor or wiring problem.
There are some signs of car AC thermostat malfunction:
- The thermostat is unable to sense the temperature.
- The thermostat is unable to control the compressor.
- The thermostat is unable to communicate with the other sensors.
To test your thermostat, you need a multimeter, jumper wire, and a test light. You can find videos online that can help you walk through the testing process. If it turns out that your AC thermostat needs replacement (for example, if it’s stuck in one position), you’ll need to take your vehicle to an auto repair shop for assistance with this task.
An AC system with no thermostat has to rely on other sensors and external factors to control the compressor.
We’ll start with a simple question: does your AC system have a thermostat? If it does, when the outdoor temperature drops low enough (usually around 60 F), your AC will turn on. But what makes the unit turn on? The answer is actually pretty interesting.
AC systems with no thermostat rely on a few different sensors to maintain an ideal indoor temperature. One of the most important ones is in your ceiling, as you may already know. This is where your furnace and air conditioner connect to each other, and also where all of the ducts come out of. From there, they run through framing into your living area. In this space, they are usually insulated by fiberglass insulation and metal pipes that carry hot water to heat up the air inside that room so it can be circulated throughout the house via fans.
But what happens when we lower temperatures outside? Well, first off, this means our heat exchanger wants to keep its heat in place—that would be too much work! So if we sense that something’s coming from outside, our system turns on so it can keep itself at an optimal setting. At a minimum temperature of 60 degrees Fahrenheit or 16 degrees Celsius, though, our AC unit will cut power to itself using one of these sensors below:
Thermal switch: This sensor has been installed for decades now and is used by many manufacturers to cut power at a certain cold-temperature threshold set by them (some brands will use their own thresholds). It’s made up of two pieces; one sends power down between wires after detecting heat outside the house and then shuts down once no more heat is detected in either area or because there isn’t any more power coming from an external source like a circuit breaker tripped off due to low voltage conditions caused by low temperatures outside (these lows cause switches being tripped off just like this one). The other piece detects when there’s no more heat inside since no more hot water comes out of you
