Why Does Honda Civic Ac Blows Cold Then Hot Air?

Imagine sitting in your honda on a hot sunny day you fire up your ac and it is blowing cold ac but a few seconds later it starts blowing hot air, just enough to ruin your day. But the question arises why does honda civic ac blows cold then hot air?

There are numerous reasons why your air conditioner may cease to function correctly throughout the day. These are some of the first things to look for if your air conditioner isn’t blowing cold air.

Why Does Honda Civic Ac Blows Cold Then Hot Air?

A car air conditioner begins cold and gradually warms up. It appears that the air conditioner is deceiving you. There are several reasons why a car air conditioner blows cold air instead of warm air.

1. Faulty Compressor Clutch

To transfer engine power to the compressor, an AC compressor clutch is used. With continuous use, the compressor clutch suffers wear and tear, causing the clutch gap to widen. As a result, it is difficult for the clutch to maintain proper pressure and force the compressor to cycle on and off. As a result, the AC compressor operates on an intermittent basis.

2. Relay Corrosion

A relay is an electromechanical switch that controls a large amount of current with a small amount of current. The relay has a coil that, when activated, attracts the contact, connecting the high-amperage circuit. As this coil ages, its internal resistance rises.

As a result, a corroded relay will cut the current if its internal resistance rises due to heat, causing the car air conditioner to blow cold rather than warm.

3. Leak In AC System

honda civic ac blows cold then hot

The most common cause of a car’s A/C gradually losing its cool is a small refrigerant leak. A leak is typically caused by a combination of moisture and refrigerant, which when combined produces a corrosive acid that eats away at A/C system seals, valves, and hoses. Because there isn’t enough refrigerant in the system to cool things down, a leak in your A/C system could be causing the unit to blow warm air.

4. Broken Fuse

honda civic ac blows cold then hot

The A/C system in your car is a maze of wires, switches, relays, and fuses. Under normal operating conditions, these components work together to provide power to the A/C unit, allowing you to have cool air on demand.

If even one of these components fails, your air conditioner may shut down and caused honda civic ac blows cold then hot. While this helps to prevent dangerous electrical fires, it also means that a single-blown fuse can cause your entire air conditioning system to shut down.

5. Clogged Air Filter

When the filter in your cooling system becomes clogged, the air conditioner struggles to move air through the system. This can cause your air conditioner to blow warm air.

When attempting to determine why your air conditioner isn’t cooling your home as effectively as it should, the first step is to ensure that your air filter is clean. If you notice that the existing air filter isn’t clean enough, replace it to see if the problem is resolved.

Inspecting And Fixing The AC

One of the most common types of A/C system-related faults is an inoperable A/C compressor clutch. When problems of this nature occur, the gases in an A/C system fail to circulate, preventing cooling.

honda civic ac blows cold then hot

1. Checks on Compressors

Begin with the air compressor. If so, the compressor is operating and the A/C system contains enough refrigerant to produce cold air, indicating that the problem is within the HVAC unit. Change the motor that operates the blend air door.

If the compressor does not engage when you turn on the A/C, try jumping the clutch wire directly to the battery to see if it will run. If you jump and the A/C blows cold air, the system contains refrigerant and the fault is most likely a bad clutch relay, clutch cycling switch, or pressure switch.

2. Checks for Refrigerant

Connect an air-conditioning pressure gauge to the HIGH SIDE service port. The gauge will indicate whether or not there is any pressure in the system. Depressing the service fitting valve with a small screwdriver to see if any refrigerant squirts out is NOT an accurate test because it only tells you how much pressure is in the system. It may still have some pressure, but not enough to trip the low-pressure safety switch and activate the compressor.

If your A/C system is low on refrigerant or has run out, check for leaks and have the system vacuumed to remove air. After the air has been removed, the system can be recharged with the specified amount of refrigerant.

3. Fixing Clutch Compressor

A non-functional or intermittent air conditioning system is the most common symptom of a bad AC compressor clutch. When the clutch engages and disengages constantly, you may notice loud noises coming from the engine. We have added video tutorial for better understanding


Step 1:

Using the appropriate size wrench from your wrench set, remove the air conditioning accessory belt. Disconnect the magnetic coil connector on your compressor. Remove the 6 mm bolt in the centre of the AC clutch with the appropriate size socket.

Step 2:

Remove the clutch and look at the spacers on the shaft behind it. They are used to properly gap the clutch, so keep them somewhere safe to avoid losing them. Remove the snap-ring that secures the pulley to the shaft and slide it off.

Step 3:

Thoroughly clean the shaft and other components before installation. Insert the new pulley and snap-ring, with the bevelled edge facing outward.

Step 4:

Install the clutch and tighten the 6 mm bolt.

Step 5

To ensure proper clearance, place the feeler gauge between the clutch and the pulley. Remove the clutch plate and add another spacer if the clearance is not correct.

Examine the air gap to ensure that the clutch engages properly. If the air gap and/or clearance are incorrect, your clutch may wear out faster. Connect the electromagnetic coil to the connector

4. Refilling Refrigerant In The AC

Anyone who can follow instructions can recharge a car’s air conditioner. Grab your safety glasses and gloves, as well as the refrigerant and attachment hose. We have added a video tutorial for you to work along the process and to fix honda civic ac blows cold then hot


1. Start the car, put it in the park, and apply the parking brake.

2. Set the air conditioner to the coldest setting, crank up the fan to the highest setting, and press the recirculate button.

3. Remove the plastic cap from the AC low-pressure service port located between the compressor and the evaporator.

4. Connect the hose to the low-pressure point while the attachment hose is disconnected from the can of refrigerant. Look at the included gauge and rotate the temperature dial to the current temperature while the compressor is cycling.

5. Do not recharge if the pressure reading is in the red portion of the gauge. This is an indication of a larger issue, possibly a faulty or malfunctioning compressor. If the PSI reading on the gauge is less than the designated “full” area, more refrigerant is required.

6. Take the hose out of the service port. Remove the safety tab from the refrigerant can, shake it, and reattach the gauge.

7. Connect the hose to the low-pressure service port and start recharging the system with refrigerant using the trigger. To maintain good refrigerant flow, rotate the can up and down.

8. When the system is full, use the built-in gauge to determine. Don’t charge too much. Remove the connector from the port and dispose of any empty cans.

Cost Of Repairing AC

In general, having one’s A/C system recharged with refrigerant will cost between $100 and $250. This assumes there are no major system leaks and that refrigerant levels have only decreased gradually over several years.


We hope this post must have helped you to diagnose and fix what caused honda civic ac blows cold then hot. If your car’s air conditioner blows cold then warm, go to your nearest Auto Care. An A/C performance check is the simplest way to find out what’s wrong with your car’s air conditioner. Make an appointment.

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