thats the relay to engage the a/c compressor clutch
The 2002 Toyota Camry air conditioning magnetic clutch relay switch can be found on the firewall in the engine compartment. The relay switch will be on the drivers side firewall.
The ac compressor clutch is mounted on the front of the compressor and is a replaceable part. However depending on the complexity of the clutch change out it may be overall better to change the compressor and clutch together.
Remove the belt from your Mercedes-Benz 240 air conditioning compressor. Remove the air conditioning hoses. Remove the compressor retaining bolts. Reverse the process to install your new air conditioning compressor.
The 2002 VW Jetta air conditioning relay switch can be found in the fuse box. The air conditioning relay switch will be in the third column, second from the top.
Try jumping the two terminals of the wires which go to the low pressure switch. That's a possibility, as is low refrigerant, a bad compressor clutch, or a faulty fuse or relay to the compressor clutch.
After doing some checks, there doesn't seem to be one! The system is activated either automatically by differential temperature between the inside and the outside, or manually from a push button on the dash. This operates an electrical clutch on the compressor, which is driven from the drive belt.
It could be low on coolant. If your vehicle is a 2002-2004 it is probably the magnetic clutch relay as it is a common problem with those years. It is located in the fuse box and a new one runs around $60.
Remove the Freon from the compressor. Remove the air conditioning hoses. Remove the compressor belt. Remove the compressor retaining bolts. Reverse the process to install the new air conditioner compressor.
The 2002 Dodge Grand Caravan air conditioning recharge valve is located on the air conditioning compressor. The recharge valve will be labeled as such.
The ac clutch is held on with a single nut, and can be removed with a remover tool. It the tool will not fit in the space available, then the entire compressor will have to be removed to replace the clutch.
You will need to connect your Freon bottle to the low pressure port on your 2002 Chevy Cavalier air conditioning compressor. Release the Freon into the compressor. A Freon recharge kit will come with everything you need and instructions.