Ford FONN‑7Z319‑BA is a shift control module used in heavy‑equipment transmissions, typically providing torque‑converter lockup and gear‑shift logic for Ford/New Holland loaders and tractors. Common failure points on this class of modules include burned fuse contacts, damaged PCB traces from vibration or moisture ingress, and degraded power‑regulation ICs that cause erratic shift timing or loss of lockup function. Begin diagnostics by verifying the 24 V input supply to the module, inspecting for correct voltage under load; check all connector pins for continuity and corrosion, especially the high‑current drive lines; then review any diagnostic trouble codes (e.g., P2Axx) from the vehicle’s ECU and perform a visual inspection of the PCB for burnt components or loose solder joints.[oss-gpt-20b]