Ok I found this thread http://www.supramania.com/forums/showthread.php?46690-SAFC-Wiring-Diagram-for-89-92-Supra-NA-and-Cressida for installing it. I've drawn out the pins so I know which wires to splice but what I can't figure out is that the ECU pins list two rpm signals and only one ground and the lower half says two grounds and only one rpm signal. Am I looking at this all wrong?
