resurrecting an old thread, I wanted to clarify/ask a few things.
I'm in the middle of a VVT into 91 NA swap myself. My ECU is a MS3-Pro using Westfieldmx5's custom board. It's made for a 90-93 MX-5 and unses the original ECU connector.
I want to use the internal alternator control circuit that I still have to solder to the board. Once I'm done building the circuit, how do I connect it to my ECU? If I understand Braineack correctly, I have to
- run the White/Green wire (99-00 wiring harness color) from the 99 alternator to the F_Out pin at the ECU, and
- run the White/Blue wire (99-00 wiring harness color) from the 99 alternator to the 12V pin at the ECU
But since my 90-93 pinout doesn't have a F_Out pin, i can randomly pick on. In my case, I could pick connector pin 1D of the 90-93 ECU connector, run a wire jumper over to the 99-00 side of the board and connect it to the hole 1O of the not-installed 99-00 ECU connector.
1O should be connected to the internal alternator circuit of the board, right? I guess so, because in the 99-00 pinout the pin 1O (GY/R color wire) is labelled as "Alt. F_Out"
yellow jumper wire to get alternator F_Out from 1O (99-00 connector) to unused pin 1D at 90-93 connector
1D (W/G) seems to be free, ready to be the future Alt. F_Out pin
Please be kind to me. You're talking to a mechanically skilled guy who still has to get comfortable with electric circuits