My ac system is empty and the compresor will not engage to fill or check for leaks ,how do i make the compresor come with no freon?

If the system is low or has no Freon, the clutch will not engage. Hook up a pressure tester on the low pressure line valve. It should read 30 psi at 65 degrees outside temperature and 50 psi at 85 degrees outside temperature. If there is pressure, then it could be a fuse or AC relay. If there is no pressure, then add freon with some pag oil, plus a leak dye will have to be added to the system from the low pressure valve. Only add 1 16 Oz. can to not over pressurize the system. If the clutch engages, then check for a leak. I would recommend taking this job to a qualified technician, since he would have the necessary equipment to put the system at a vacuum of -30- To empty the system and check for a leak.

My Jeep did the same thing, i had to first buy a little can of dye at AZ and run it through the system where you fill the freon. It will show you with the help of a UV light if there are any leaks in the AC pump, it will glow purple if it is leaking. Usually tho you can't just fill the AC w freon all the time, a mechanic will have to purge the AC system. I cannot remember the name of the unit but there is a canister that needs to be purged before just adding freon. It sounds like that is what's going on since the pump is engaging.

There are 2 safety switches in most A/C systems. A high and low pressure sensor will cut off the Compressor clutch. You can borrow a gauge set, called Manifold gauges, from tool loaner programs at Autozone, Advance, or Oreilys autoparts.

There are several ways to try to fix this. It depends on what the pressure gauges show.

If the pressure is low, but not empty, there is hope. The old Freon leaked out. It will happen again. But there are products which can plug some leaks. Then add Freon using the gauges. The ideal amount is an amount that makes the compressor stay on the longest. There are gauges that can tell you, color coded, and reasonable priced.

If the system is completely empty, it is contaminated with outside air. The Freon will not function correctly if added and a new Dryer(A/C part) should be installed. There is a Vacuum pump which must be attached to draw down the system to a negative vacuum. So even changing a part will not decontaminate the system without the pump. Pump can be loaned from Autozone with big deposit which is returned, no hassle. Some parts require special pliers and "O" rings to reinstall.

The price of Freon has skyrocketed. What once costed $12 to refill a car now costs $50. So going to a repair shop can be a better idea if you waste Freon doing it yourself. If you don't repair the leak, imagine $50 evaporating into the wind with the Freon.

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

Check to see if A/C clutch is engaging. If it is not engaging, the compressor is not starting which will prevent the freon from being sucked into the system.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Probably means a significant leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch.

However, if it is empty the leak must be repaired.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 36 psi.

you need to put a pressure gauge on the freon input nozzle and see how much freon is already in your system You are probably getting no cooling because the clutch on the front of the A/C compressor is broken, or the switch on the dash is not opening the vents inside correctly. Putting more freon into an already full system can have unpleasant results. So if when checking the gauge, the freon levels are ok, next, run the car, and look at the front of the A/C compressor.see if the clutch clicks in and out as the A/C is turned on/off. If the clutch free-spins all the time it needs to be replaced, or if its silent completely, the wiring to the A/C needs to be checked. If the clutch is ok, head under the dash ad listen for the vent doors opening and closing as you cycle the A/C on/off. If you can't hear them, a vacuum pipe or electrical connection/A/C switch is to blame.

hi BE SHURE TO CHECK THE FREON GAS YOU ARE FILING IS COMPATIBLE WITH THE R12 IN THE SISTEM.THE R12 IS THE ORIGINAL FREON GAS THAT MODEL CAME WITH.IF THE AC SISTEM IS EMPTY THE AC COMPRESOR WILL NOT OPERATE UNTIL IT HAVES SOME GAS PRESURE SO WHEN YOU FILL THE SISTEM WITH THE FIRST BOTLE OF FREON IT WILL AUTOMATICALY START TO OPERATE ON AND OFF UNTILL THE SISTEM IS FULLY CHARGE