Where should the negative power return of a mobile transceiver be connected in a vehicle?

When installing a mobile transceiver, the negative power return should be connected to the 12-volt battery chassis ground. This is the specific grounding point where the battery's negative terminal connects to the vehicle's body. Modern vehicles use sophisticated battery management systems with current sensors attached directly to the negative battery post. Connecting your radio directly to the negative post can bypass these sensors, causing issues with the vehicle's charging system and computer. Connecting to random metal parts under the dash or to the radio's mounting bracket is a poor practice. These improvised connections often have high electrical resistance and can introduce severe alternator whine or ground loop noise into your audio.