Possible problem with IAC wiring diagram

jimjovan · Post by **jimjovan** » Mon Apr 24, 2006 8:03 pm

I think there might be a problem with the IAC wiring diagram for stepper motors with the "in-line" connector.

I installed MS-II on my Miata and used a in-line IAC motor. The motor has the coil configuration as in the top wiring diagram on the "Idle Air Control with MegaSquirt II" web page (coil 1 connected to the outer pins and coil 2 on the two inner). The problem is in the DB37 pin assignments. I originally wired it as in the diagram and the motor did move sometimes, but it never worked as it should.

I believe the DB37 pin call-outs should be X5 (#31), X2 (#25), X3 (#27), and x4 (#29). In the current diagram X2 is #29 and X4 is #25.

If you look at the external wiring diagram for MS-II, pins #25 & #27 are for one coil and pins #29 & #31 are for the other.

I rewired my stepper motor with the above changes and now it works great!

If someone out there with more experience could look into this, I would greatly appreciate it.

Thanks,

Jim

Bernard Fife · Post by **Bernard Fife** » Mon Apr 24, 2006 9:34 pm

Jim,

Yes, you are right, of course, and I have fixed the diagram. Sorry for misleading you, and thanks for bringing it up - it's the main way to clear up errors in the manual.

Lance.