The MS3Pro EVO harness is very similar to the original MS3Pro harness – the major differences are that we have repurposed the USB and serial wires for extra analog and VR inputs, and since the MS3Pro EVO has an internal MAP sensor, the MAP wire has been renamed Analog In 6. All other pins besides the serial and USB connections will still work for their original purpose on a Gen 1 harness.

The inline USB cable used on the first generation harness can be bought from Digi-Key under part number AE10162-ND.

You will connect the wires to the wires the MS3Pro EVO used for digital frequency VR inputs – look for the two shielded cables on the gray connector. You will need to make sure the USB only connects to the inner wires in the cables and that the shield and bare wire do not connect to the USB wires. Here is how to match up the USB wires for the cable in the link above.

  • MS3Pro pin 22 connects to the red wire in the USB cable. On the MS3Pro EVO harness, this is the purple Digital Frequency VR 3+ wire. It is bundled along with a blue wire.
  • MS3Pro pin 23 connects to the black wire in the USB cable. This is the blue Digital Frequency VR 3- wire.
  • MS3Pro pin 34 connects to the white wire in the USB cable. This is the purple Digital Frequency VR 1+ wire, which is bundled with a white wire.
  • MS3Pro pin 35 connects to the green wire in the USB cable. This is the white Digital Frequency VR 1- wire.

You would wire the MAP sensor to Analog In 6 – this is already done on our drop on harnesses, which include connectors for the stock MAP sensor. If you wish to splice in an RS232 serial cable, use these wires on the white connector.

  • Pin 17, Analog In 7, with a green and orange wire is used for serial ground.
  • Pin 22, Analog In 4, with a light blue and pink wire is used for serial TX.
  • Pin 23, Analog In 5, with a blue and orange wire is used for serial RX.

Since you only need one or the other, we expect most users will opt to use the USB connection, but RS232 can help if you run into electrical noise issues.