I am starting to wire up my harness and i have run into what seem's like a little problem. I have been following along with jobro's guide to getting the megasquirt ready to run. Now that im getting the wiring harness ready to go(i am using the one that came with my ms from diyautotune) i see that my harness has grounds at 7 8 9 and 17 18 19 and all the pics for wiring show grounds at 8 9 10 11 and 15. They also show that you wire the cas up to pin 7, being that it is a ground in my harness should i just go ahead and wire it in or should i run a seperate wire in the harness?

 

More to the point im asking does the 24 tooth vr sensor negative have to be wired to pin 2 or 7? I see that my harness has a shielded cable that connects to pin 2(shielding) and pin 24.

 

It doesnt have to be, but pin 2 is a ground that runs through the MS before being connected out to the block thru pins 7-10 or 7-12 typically. For the 24 tooth sensor, it references against the common ground IIRC, so you need to connect the Ne- to some type of common ground pin at the MS, and preferrably one that won't have lots of current running through it, such as pin 2