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flightlead404 flightlead404 is offline
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Originally Posted by fasteddie313 View Post
OK, I am afraid to fry something..
What MS wire(s) should I connect to the "a - To Tachomiter" on my ignition system?

VRIN+ to it?
opt+ and then ground the opt-?

Megasquirt says something about not to do this with a certain type of CDI (negative side of coil) and I'm not sure if mine is that and this tach output goes to the coil also..

Fuel pump priming is working but I'm afraid to fry my box with this tach signal..

Also, I have the innovate MTX-L.
It doesn't have what I would think of as a "sensor ground". It just has a ground for the whole thing..

Should I ground the MTX-L to the MS shared ground?
I have it just chassis grounded right now and it's working independently..

1 more thing.. Their are 2 "shared ground" white/blk wires in my MS harness. They go to different pins..
Are they the same? Go to the same place in the MS box? Use one or the other or both?
I believe M(1) is the coil negative on that diagram, which is also connected to a, and to pin 16 on the ignition unit.

N(a) (distributor) looks like the signal wire from a reluctor pickup, which is connected connected to O (31) on the ignition unit.

O(31d) is the shield for the reluctor.

O(31) looks like GND and

15 looks like its +12v everywhere

I'm not sure you have a choice here, I don't see a tach output from the ignition unit the way we have one on the 930's.

You could put an O scope on the output and see what it looks like first.

I connected my TD output from the CDI box to Opto+ and grounded opto-, VRs I left floating. That works for me, but the TD output is, roughly a 5v square wave iirc

Last edited by flightlead404; 06-13-2018 at 04:01 PM..
Old 06-13-2018, 03:58 PM
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