Part Smart is here to help you discover, diagnose, and learn about underlying issues that could affect your vehicle’s performance. Our latest Part Smart Article covers the 05-06 Ford Expedition with a computer-controlled alternator. The problem may be with the alternator’s regulator connector, which sends a signal through the wiring harness to the PCM so the PCM can determine the vehicle’s electrical load to maintain the proper voltage set point. If there is an issue with the wiring harness, the alternator’s signal cannot reach the PCM and could cause a no charge issue.