Miata Turbo Forum - Boost cars, acquire cats. - Rccote's MS2 V3 misc build questions

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- - Rccote's MS2 V3 misc build questions (https://www.miataturbo.net/megasquirt-18/rccotes-ms2-v3-misc-build-questions-30114/)

Quote:

Originally Posted by rccote (Post 353960)

So on to the harness. I'm going for boomslang and there are three turquoise contacts on the diagram: Fans, Idle and Clutch. What has got me confused is I've only got one of the three coming off the DB37 and that is idle. Am I supposed to just connect idle and forget about the other two?

By this do you mean you're doing a parallel install or standalone?

I do not have anything hooked up to the clutch, I believe you need that for launch control if i'm not mistaken, i could be very very wrong though.

As for fans, if you're doing standalone you absolutely need to hook that up. If you followed brain's writeup I think it outputs fans on pin 27 but doublecheck me on that, i could be wrong again there too. I have shit for memory.

I'll assume you're referring to the turquoise contacts on this diagram.

If you did the "fans" mod in post 4, then your fan control pin on the MS is IAC2A, which is pin 29 of the DB37. On your '90, the cooling fan is normally activated by the thermoswitch on the thermostat housing. If you wish, you can leave this as-is, and go no further here. If you wish to be able to use the MS to control the cooling fan, then connect pin 29 to the black/green wire at 1R on your ECU harness.

The clutch connection is used for launch control. I see no indication in the HowTo of the clutch input circuit being built, however here is the section of the MSExtra manual that discusses it, and how to build the input circuit for it. To what pin on the DB37 this connects is up to you. Any of the unused SPR or IAC pins can be used for this.