If the battery is disconnected, several systems must be re-learned before they will work properly. The refrigerant desiccant cartridge should be replaced whenever the compressor is replaced. Have the air conditioning system discharged. Remove the engine cover and disconnect the negative battery cable. Loosen the right front wheel bolts, then raise the vehicle on the hoist and remove the under-vehicle splash shield. Depending on the engine, it may be easier to remove the right inner fender splash shield. Remove the drivebelt and the air filter housing. On turbocharged models, it may be necessary to remove the charge air cooler pipes. Clean the compressor thoroughly around the refrigerant line fittings. Disconnect the electrical connectors from the top and back of the air conditioning compressor. Remove the compressor mounting bolts, detach the compressor from the mounting bracket, and lower it from the engine compartment. Disconnect the suction and discharge lines from the compressor, plug the open fittings to prevent the entry of dirt and moisture, and discard the seals between the plates and compressor. If a new compressor is being installed, pour the oil from the old compressor into a graduated container and add that exact amount of new refrigerant oil to the new compressor, following any directions included with it. Some replacement compressors come with refrigerant oil in them, so follow the directions regarding the draining of excess oil prior to installation. Installation is the reverse of removal; when installing the line fitting bolt to the compressor, use new seals lubricated with clean refrigerant oil and tighten the bolt securely, ensuring the alignment sleeves in the compressor bolt holes are seated correctly and the contact surfaces are clean and flat. Have the system evacuated, recharged, and leak tested by the shop that discharged it.