8-Foot Wiring Harness

The MegaSquirt 8′ Wiring Harness from DIYAutoTune is meticulously designed to provide a reliable, clean, and straightforward wiring solution for MegaSquirt EFI systems. Constructed from high-temperature TXL automotive-grade wire, this 8-foot harness is built to withstand demanding engine bay conditions. Thoughtful engineering is evident throughout, with features like clearly printed wire labels every 5 inches, eliminating the need for paper tags. The ignition input cable is twisted and shielded to significantly suppress noise, while the injector outputs utilize dual smaller wires to reduce splice count and improve signal integrity. A dedicated sensor ground wire ensures clean signal returns, and the heavy-duty metal DB37 hood provides robust EMI/RFI shielding. The DB37 connector is pre-crimped and machine-terminated, bypassing solder cups for a more reliable connection. Additional enhancements include thumbscrews on the DB37 for tool-free tightening and wiring for CAN bus, expanded I/O support, IAC, and ignition circuits. This harness is directly compatible with MegaSquirt-3 (MS3) with MSX Expansion, MegaSquirt-3 (MS3), and MegaSquirt-2 (MS2) systems that connect via the ECU's DB37 port. For users employing a relay board, the MegaSquirt Wiring Bundle is recommended instead. It is important to note that this MSHarness is not compatible with the MegaSquirt Relay Cable; only one of these components should be used in your setup.