Pinky

iTrader: (1)

I'm installing an 04 Mazdaspeed Miata drivetrain into my 99 Miata, with a MS3X running it. The 99's coils got their 12v+ directly from the main engine relay and had no condenser; the 04 MSM coils got their 12v+ from pin 4S on the stock ECU and had a small condenser bridged onto the circuit.

I'm using the stock 99 under hood harness with a DIYBOB to patch in to the MS3X. I've replaced the 99 coil connectors with the ones that fit the 04 MSM coils, connecting 12v+ to 12v+, ground to ground, and the logic/triggers to the coil 1 and 2 on the MS3X.

Do I need to splice the condenser back onto the 12v+ feed, or can I ditch it? In other words, is there anything specifically different about the MSM coils that requires its presence, or was it just there because they had been getting their 12v+ from the MSM ECU?

Thanks in advance-

Braineack

iTrader: (62)

your 99 has one connected somewhere...

Pinky

iTrader: (1)

I've checked the 99 wiring diagram thoroughly, and there isn't one, unless perhaps it was integrated (internally) in the coils themselves.. (?)

At any rate, should I splice it onto the 04 coils 12v+ feed?

Pinky

iTrader: (1)

Oh, one quick correction to my original post- the 12v+ feed on the 04 coils did come from the main power relay, fed the coils *and* was connected to the MSM ECU, which I guess was monitoring the voltage or something.. (I don't have a pin chart for the 04 ECU telling me it's function. That same black-white 12v+ line also supplied voltage to the O2 sensors..