How to Megasquirt your 3G Hemi

Time for the Outputs:
Logic level spark (12v fused feed and box controlled ground, through coil drivers, to fire coils):
*the MS3x box ‘fires’ the coils by grounding the connection. So, all coils share a common fused 12V, but each has a different ground connected through the coil driver to the MS3x box.
12v fused feed- from fuse box powered by the fuel pump relay. Powers all the coils.
Ground – run the ground wire from the box to the coil driver, and from the coil driver to the coil. Coil wires are labeled, and are on the MS3x plug. The hemi firing order is:
• Spark A - cylinder 1
• Spark B - cylinder 8
• Spark C - cylinder 4
• Spark D - cylinder 3
• Spark E - cylinder 6
• Spark F - cylinder 5
• Spark G - cylinder 7
• Spark H - cylinder 2
*the order is of course the same when wiring the injectors


Injectors (12v fused feed and box controlled ground to fire injectors)
*the MS3x box ‘fires’ the injectors by grounding the connection. So, all coils share a common fused 12V, but each has a different ground connected to the MS3x box.
12v fused feed- from fuse box powered by the fuel pump relay. Powers all the injectors.
Ground – run the ground wire from the box to the corresponding injector. Injector wires are labeled, and are on the MS3x plug.


Idle air control (not installed by me- there is no idle air control on a hilborn) (should be 12v fused feed and box controlled ground to operate)

Tach signal (single signal wire to run to tach input)
Pin 26 on the MS3x plug.