2003 BMW X5 A/C

You don't want to jump anything there. That is not an off/on type of switch. It's a sensor that feeds data to the computer. If you put a minimal amount of refrigerant in it and reset the computer, it will energize the compressor if it doesn't have any other problems.

Thank You for your help wrenchtech. To reset computer do I just disconnect battery for two min or is there an alternative method on theses vehicles?

Disconnecting the battery should be sufficient but don't do that unless you have to because you will lose all the other memory also.

Thank You for your help.

The response from Wrenchtech is correct and I agree with it. The lack of refrigerant is the cause, the IHKA system will see the logic from the pressure switch and begin to work if there is enough refrigerant in the system, it won't require a reset. A/C systems require special tools and equipment to be serviced correctly. They also operate at high pressures and repairs should be done by trained technicians.