Overview
An extremely low-cost v1 wire harness for our FSAE internal-combustion car. We started with a connector-to-connector pinout in KiCad — every ECU, sensor, and actuator connection mapped pin by pin — and then turned that into a complete engine and chassis harness: ECU, the full sensor set (TPS, MAP, coolant, crank, cam, oil pressure, IAT, VSS, O₂), ignition coils, fuel injectors, fuse boards, dashboard switches, and the starting/charging power path.
What it taught us
The v1 was as much a learning platform as a deliverable, and it drove home the fundamentals that make a harness reliable:
- Strategic branching — where to break the loom out and splice so it routes cleanly through the chassis, stays serviceable, and keeps runs short.
- Star grounding — bringing analog grounds back to a single reference point so sensor signals stay clean.
- Appropriate wire sizing — matching gauge to current and run length instead of guessing, and fusing each branch to match.
Those lessons carry straight into this year’s car.