I have a 2008 Ford F350 and I'm having issues with my electrical system. The instrument panel gauges all drop and battery light comes on, heater blower goes out and the radio goes off after a bit. We have put new batteries as well as a new alternator and have checked the fuses for the instrument cluster. The alternator was replaced approx. 2 weeks ago and the new batteries were put in yesterday with no remedy for the issue. Any help as to figure out where to start my search for the problem would be appreciated. Thanks so much!