How to Audit a J1939 Harness Supplier for Alternator Ripple and Common-Mode Noise Control
When a fleet calls me about a J1939 communication fault, the complaint is rarely “the bus is dead.” It is usually an intermittent SPN 639 or SPN 168, a U-code that clears after the truck sits overnight, or an ECU that drops off the bus only when the alternator is loaded and the engine is […]