Spent some more time on it today.
There are really only 9 wires that need to be spliced in from what I can tell so far. Its this 9 wire plug that goes underneath the dashboard and over to the computers:
The wires on ours was identical to the one in this image with the exception of the location of two of the wires. We had a Red/Black in the top right for the speedo wire and a Blue wire in the very middle for the wire to the igntion switch.
On ours, these 9 wires are as follows:
Yel/Red: Power Relay. Pin 87/2 (Fuel Pump)
Grey/Red: ecu pin 15. A/C Delay Relay
Red/Blk: ecu pin 35. 12v Switched
Purple: ecu pin 14. Instrument (Shift Indicator)
Blue: ecu pin 34. Speedo wire. Connect to cruise ouptut (dual male connector on back of cluster)Green: ecu pin 26 (A/C dryer pressure switch)
Yel/Blue: ("Starter" service socket) Not used
Yel/Red: into harness. (Heated O2.)
Pink x2: ecu pin 22. Inst. connection (Check engine light)
icu pin 43. Inst connection (Check engine light)
This plug went directly into the existing 1984 240 Turbo chassis harness. The 4 wires on the 2.4 harness correlated exactly with the wire colors on the chassis harness, so all that was needed was to plug it in. Like mentioned above, they serve these functions:
Red: Alternator stimulator wire
Yellow: Coolant temp for guage
Black: Oil pressure warning light wire
Yellow/Blue: Starter