The compressor relay is located under the steering wheel. It is necessary to remove the lower protection, under which the relay unit is located. There are several relays, one of which is a compressor relay. There were cases when by mistake they replaced a wrong relay, which led to the failure of the air suspension compressor, as the native relay was jammed, and the compressor worked even with the shut down engine. You need to be very careful when you are replacing the relay.