its after page 101 but it only shows the turbo harness

 

It may seem daunting, but there's a unique quirk about Series 4 RX7s. All of the connectors are named after the harness they are on. One of the ECU connectors is on the Front Harness, so it is designated F-31. Connectors that link harnesses together have a similar designation. Underneath the Glove Box is where the Front and Emission Harnesses come together via connectors aptly named FEM-01 and FEM-02.
F: Front Harness
E: Engine harness
EM: Emission Harness
R: Rear Harness

For Series 5 (89+), names were redone according to what system it belonged to. For example, the ECU is the most important part of Section B: Engine Control, so its new designation is B1-01 (non-turbo) or B2-01 (turbo). Harness-joining connectors all were lumped into Section X, so they all have X-01/X-02/etc designations. If you understand what harness you're looking at, then match wire colors/pinouts/connector shapes, you have everything you need to identify each connector. A good starting point for this is the headlights, as they are part of the Front Harness and have an unmistakable shape (6054 bulb connectors are the same as H4 bulb connectors)

Just remember to read the pinouts from the REAR (wire side, not terminal side) and everything will line up correctly. This trips up a lot of people, even me. Especially when reading diagrams in Japanese and the wire colors are in Kanji. OR if they decide to flip things around and do it from the Terminal side like on the Spirit R in a few places. Must have been a Tuesday and someone had to look busy...:P