Scotty Kilmer - How to Fix Car AC that's Not Blowing Cold Air

Rev up your engines! It's time for the Scotty Kilmer Channel. If your car's air conditioning isn't blowing cold, stay tuned, because today I'm going to show you how to fix an air conditioner that isn't blowing cold.

Now, to check your air conditioner, put it on maximum air conditioning, and turn the blower on to high. Then look under the hood at the compressor to see if it's running. Look at the front of the motor and go down to where the compressor is, right down here. If you see that the end of the compressor is running, then you know at least the system is operating. In this case, you see the compressor is running. But if it's not running like this, here you can see the front isn't spinning, so that means that the compressor isn't operating. If the compressor isn't operating, then you have to figure out why it's not operating. But in this case it is working, so let's check the pressure.

Pick up your air conditioning gauges, and don't worry, they don't cost that much. You can get them at places like Harbor Freight Tools for 40 bucks. Then get the low pressure fitting and put it on the low pressure fitting on the engine. In this case, that's right here. Just unscrew the cap and put the fitting on. Then read the pressure on the gauge, which in this case is only about five pounds. With the air conditioning running, the low side pressure should be thirty to forty pounds. This is only five, so odds are the system is just low on refrigerant.

Now, all air conditioning compressors on cars leak a little, because they have rubber seals on the shaft here. They have to leak a little to lubricate the shaft, or the seals would burn out. So it's totally normal to have to add some refrigerant every once in a while.

Now, the most correct way to put refrigerant in the car is to empty out all of the old refrigerant with a vacuum pump, and then get a can of refrigerant and use a scale that measures how much goes into it. I show how to do this in my YouTube video, and you can watch this other YouTube video to see how to do that. Here it is on YouTube in case you have a hard time finding it.

If you don't have all this equipment, you can use the gauges and get an approximate fill. Just hook up refrigerant to the gauge and turn it open, then watch the pressure on the gauge. Get one of these little thermometers to stick in the vent to see what the temperature is. Just stick it in a vent closest to the middle. Then, when the pressure gets to be between thirty and forty pounds, shut it off and see how cold the air is. Just turn off the valve on the can, then check the temperature on the thermometer. In this case, it's about 38 degrees, and I'm feeling better already.

So the next time your air conditioning has you hot under the collar, fix it yourself. And remember, if you've got any questions, just visit ScottyKilmer.com, and I'll answer them as soon as I get back from this ride. One, two, three, four!