MSefi.com read only forum (Jan.15,2018)

Hello,

I just finished my ms2 build and I have 10' megasquirt main board wiring harness.

Problem: while double checking all the pins with diagram came the harness and labeling them for easy installation, I noticed that diagram indicates 30 wires while harness has only 28

Missing: wire on pin #1- ground for crank position sensor(hall) And...
Wire on pin #2 - not what does. The diagram shows it looped around the sheilded pair crank position ground for VR circuit (which I'm not using).

Any help would be appreciated.

Will

Pins 1&2 and 7-19 are all ground pins connected to the ground plane on the PCB. Which one is used for what doesn't much matter.
The important thing is to use at least four pins and suitable cables for the main ground to the engine block.

And to run all the signal grounds - TPS, ATS. CTS, crank sensor etc to different ground pins.

So that with the MS unplugged, the sensor grounds are not connected to ground - that must only happen when the MS is plugged in.

The problem with any universal loom is it may not suit your installation exactly, so need some adapting.

So you are saying that I can connect those to the other ground wires. I just did not understand why the instructions that they give you would suggest to connect to pin #1 when there is no wire connected to pen #1 in the harness.

Will

ironwill11 wrote:So you are saying that I can connect those to the other ground wires. I just did not understand why the instructions that they give you would suggest to connect to pin #1 when there is no wire connected to pen #1 in the harness.

Will

Yes it often confuses. I dunno how many ground wires your loom uses, and if they are all the same colour. But choose just one and use than for all the signal grounds. Run all the others to the engine block.