Mixed-Fleet ELD Nightmares: A Field Engineer’s Guide to Reliable J1939 9-Pin Connections
You’re staring at an 18-wheeler with a brand-new ELD that should be logging hours. The J1939 9-pin connector clicks into place, but the screen stays dark. You check voltage—fine. Check ground—fine. Yet the dashboard flickers with unexpected warnings, and the device stubbornly reports “No Engine Data.” The pressure’s on. But what if the problem isn’t […]