Why Your Test Bench OBD Cable Needs an AWG, Loop Resistance, and Ground Separation Specification
In the last two years, I have reviewed eleven test bench OBD harnesses that were shipped back from labs with “ECU reset during flash” written on the fault tag. Nine of them measured fine on continuity and failed under load. The OBD cable is passive, so it is usually the last part to be measured. A continuity test passes. […]
J1962 Pin 4 vs Pin 5: Why Bonding Them Inside Your Diagnostic Tool Creates Phantom Sensor Faults
This is the kind of fault that doesn’t show up on a bench test at twenty-five degrees Celsius. It shows up three weeks later, on a customer’s truck, at 6:40 in the morning, after a cold start, when the engine light comes on for a cam sensor that the dealer’s own tool never sees. If […]
Pressure Washing Your Harvester? Why IP67 Connectors Are the Minimum Standard for Forestry CAN Networks
I have watched a harvester operator finish a shift, open the side door, and point a hot-water pressure washer straight at the valve block. He was not doing anything careless by forestry standards. He was cleaning the machine. The CAN bus did not go down immediately. It went down the next morning, then came back after the sun warmed the connector […]
Deutsch DT vs. Amphenol AT Connectors for Articulation Joints: Lab-Tested Comparison Under Pressure Washing
The first time I watched a pressure washer kill an articulation joint connector, the housing looked perfect. No cracks. No melted pins. The wedge lock was still seated. The failure was water wicking along the wire insulation into the back of the terminal. The operator was using a turbo nozzle at about 85 bar, maybe 40 […]
Why Forestry OEMs Keep Paying for J1939 Harness Failures—and What to Demand From a Supplier Before the Next Build
The first cold snap on a northern logging block usually finds the weak harness. A forwarder or harvester will drop a node from the J1939 network for a few seconds, store a communication timeout in the ECU, and then run normally for another two days. The fault never appears on a warm shop floor. By the time […]
J1939 Termination Resistor Drift in Extreme Temperatures: Measurement Protocol for Forestry Applications
A few years ago, I spent a week at a logging operation in northern British Columbia. The mornings were around -38°C, and every day the same harvester would throw CAN bus errors until the cab warmed up. After three days of swapping ECUs, checking wiring harnesses, and reloading software, we finally measured the terminating resistor with the connector cold-soaked. […]