I am preparing to recharge a 2002 honda accord V6 air conditioner. I read a blog that stated if the refrigerant is low, the compressor won't run so am wondering if the low refirgerant pressure level may be causing the high pitched whine I am hearing from the belts on the side of motor where I believe the compressor is driven. The air conditioner has slowly stopped cooling as well over the last couple of years so that's why I decided to go the recharge route. I am suspecting the compressor will not run until I add enough refrigerant charge to the low pressure side. Any other tips about how to recharge and what to look for?

The air conditioning system on a 2002 Ford Thunderbird has a 28 ounce (0.79 kilogram) R134a refrigerant capacity according to the service manual. There should be an HVAC sticker under the hood, near the radiator or elsewhere in the engine bay that confirms this. If the refrigerant level has been confirmed as low, it would be wise to first inspect for leaks. Refrigerant leaks leave traces of oil behind, so inspect the compressor, line connections, hoses and condenser for this residue. UV dye can also be added to the system prior to charging with refrigerant to help locate the source of a small or otherwise difficult-to-find leak. You can read more about signs that an A/C system needs to be recharged here: https://www.yourmechanic.com/article/signs-your-ac-needs-to-be-recharged

Take to a shop that has the proper gauges and ability to vacuum the system properly. Do not simply try and add Freon as it only causes an air gap and false readings. In addition, some cars require a resetting of values on the cars computer brain in order to function properly.

I would check the low pressure switch next. The switch cuts power to the compressor if the pressure is too low. The switch can fail.
Same goes for the high pressure safety switch.
As for leaving the relay bypassed, you would need to use a test light or meter to see if you are using battery power with the key off. I would not recommend it.

If your air conditioner needs recharging it is because the refrigerant chemical is leaking out of the system. Many people think that air conditioners naturally leak refrigerant, so they assume they have to take the car in every year for recharging. This is not true. The refrigerant is not supposed to leak. If the refrigerant is low, find and repair the leak. There should be no reason for a recharge.

The AC compressor will not engage unless the system is charged up with refrigerant, a low state of charge due to a leak will shut the compressor off. Have a set of gauges hooked up to the AC system and have the pressures checked to see if you have a leak. You must repair the leak before the system is recharged.

I have the same problem right now, and from what I can figure, it looks like an intermittent thermal protector switch on top of the AC compressor. My 2003 Civic air conditioning works fine for 20 minutes or so and then stops working. If this switch is faulty, the compressor clutch won't engage and you won`t get cold air. I will get it replaced soon, but it seems like the access is not easy.

HI. Here is a complete check list that will help you trouble shot this issue. You will find the problem in one or more of these areas stated below.

1. Check Drive Belts - The air conditioner utilizes a drive belt that supplies power to rotate the compressor, which is basically a refrigerant pump. If the belt fails the compressor has nothing to drive it, inspect and replace as needed to restore operation. If belt is intact proceed to the next step.

2. Check for Compressor Clutch Engagement - Turn the air conditioner to the "on" position and set controls to the coldest setting. Start the engine and allow to idle. Then open the hood and inspect the clutch at the front of the compressor, is it turning? "Engaged" if so, the system has enough refrigerant to activate. If the system is low on refrigerant it will not work properly. In this case an air conditioner recharge kit is needed to recharge the system. If the system is low on refrigerant it could cycle on and off, making a ticking noise. If the compressor clutch is not turning proceed to next step.

3. Inspect for Refrigerant Leaks - If the system has a large leak and no refrigerant remains it will not activate. First test system for a static pressure charge, with the engine off attach an ac gauge to the low side pressure port and check the state of charge. Depending on outside temperature there should be between 50 psi and 80 psi. (Cool and warm). A refrigerant leak detector is needed to inspect for leak, but if you do not have a leak detector there is an alternative method. The air conditioner system is designed to run with oil suspended in the refrigerant to lubricate the system. Check for oily residue outside the system by inspecting all hoses, compressor, condenser, evaporator or receiver drier and replace any component that has failed.

4. Inspect Fuses - Check under dash panel and under hood power distribution center. Replace failed fuses as needed, recheck system. If the new fuse fails when reinstalled a short circuit is present and requires diagnosing with a wiring schematic, follow circuits to locate short, repair as needed and recheck system.

5. Check Temperature Control Vents - The vents inside your car are controlled by a cable, electrical servo or vacuum servo. If the temperature blend door is not functioning properly it will cause warm air from the heater to exit the vents. To check this start the car and allow the engine idle, next turn the blower motor speed on low, switch the temperature control from warm to cold while your ear is close to the vents. You should hear the door move inside the heater box as it swings from open to close. If not, insect for a vacuum leak or a shorted motor in the servo, repair the leak or replace the servo motor.

HI. Here is a complete check list that will help you trouble shot thsi issue. You will find the problem in one or more of these areas stated below.

1. Check Drive Belts - The air conditioner utilizes a drive belt that supplies power to rotate the compressor, which is basically a refrigerant pump. If the belt fails the compressor has nothing to drive it, inspect and replace as needed to restore operation. If belt is intact proceed to the next step.

2. Check for Compressor Clutch Engagement - Turn the air conditioner to the "on" position and set controls to the coldest setting. Start the engine and allow to idle. Then open the hood and inspect the clutch at the front of the compressor, is it turning? "Engaged" if so, the system has enough refrigerant to activate. If the system is low on refrigerant it will not work properly. In this case an air conditioner recharge kit is needed to recharge the system. If the system is low on refrigerant it could cycle on and off, making a ticking noise. If the compressor clutch is not turning proceed to next step.

3. Inspect for Refrigerant Leaks - If the system has a large leak and no refrigerant remains it will not activate. First test system for a static pressure charge, with the engine off attach an ac gauge to the low side pressure port and check the state of charge. Depending on outside temperature there should be between 50 psi and 80 psi. (Cool and warm). A refrigerant leak detector is needed to inspect for leak, but if you do not have a leak detector there is an alternative method. The air conditioner system is designed to run with oil suspended in the refrigerant to lubricate the system. Check for oily residue outside the system by inspecting all hoses, compressor, condenser, evaporator or receiver drier and replace any component that has failed.

4. Inspect Fuses - Check under dash panel and under hood power distribution center. Replace failed fuses as needed, recheck system. If the new fuse fails when reinstalled a short circuit is present and requires diagnosing with a wiring schematic, follow circuits to locate short, repair as needed and recheck system.

5. Check Temperature Control Vents - The vents inside your car are controlled by a cable, electrical servo or vacuum servo. If the temperature blend door is not functioning properly it will cause warm air from the heater to exit the vents. To check this start the car and allow the engine idle, next turn the blower motor speed on low, switch the temperature control from warm to cold while your ear is close to the vents. You should hear the door move inside the heater box as it swings from open to close. If not, insect for a vacuum leak or a shorted motor in the servo, repair the leak or replace the servo motor.

Hi there. When a compressor is replaced, two things are in fact being replaced - both the compressor and the refrigerant (Freon) and if the problem is resolved as a result which of those two replaced elements caused the original problem? Well you will never know and so before the compressor is replaced you need to have you’re A/C system recharged – it’s by far the most cost effective initial thing to do. In general A/C systems loose at least 10% of their effectiveness each year through loss of refrigerant and so given the age of your car; it’s the first thing to focus on. A professional A/C centre will also be able to tell you whether your compressor is working properly after having a refrigerant recharge by the monitoring the operating pressures in the A/C system.

is it cooling any ? and do you mean the blower turns on and off or the compressor shuts off and on ? if so its still low on freon it will run all the time if full on freon .