First let me start by saying that the ecu harness for the ka24de is different between the 5speed and automatic. when i began my swap i never herd this but i guess it makes sense. the auto harness has an additional plug just up from the ecu, i would have to imagine it connects to the transmission controller and sense no one has ever mentioned it before (so long as you dont have an automatic) it could probably go untouched and disconnected with no ill effects. I used the 5speed harness.
When wiring your dohc the brown connector on the ecu harness needs to be rewired to connect to the white body plug. most ppl simply cut off the sohc harness connector and solder it on to the dohc harness, i suggest repining.you can open the connector pin holder with a small flathead screwdriver (one holder on either side) and slip the pin out after inserting a saftey pin into the face of the connector from the center and sliding along the underside of the pin untill you unlock the seccond catch. after repining it looks like this.
The wires go into the sohc connector in the same locations thay came out of it so that the end result is a dohc harness with a sohc plug.ie black - black, red - red, and so on. what those wires do are as follows.
Black = Ground
Red = Check Engine Light
Orange = Start Signal
Yellow/Green = Speedo
Blue/Black = Water Temp
Yellow/Red = Tach
Green/Yellow = Rear Window Defrost - not used on sohc models
Blue/Green = Thermo Control Amplifier - ok so i dont really know what this is but its in both models, my guess it idles up the motor when you turn the ac on.
the next little bit here is my favorite part. i personally have every intention on getting a CONSULT cable and was quite disappointed at the idea of loosing my CONSULT port. so here is how to keep it.
first you should source a CONSULT connector from a donor 240 or other consult equipped nissan (ie junkyard) thay look like this.
wiring it up is fairly straight forward, again color match, this time i didn't repin the connector i soldered mine because i wanted it to have enough length to be accessible. (the cable is easily accessed through the glove box, great location!)
Green = RX
Green/Black = TX
Green/White = Clk
the next two take a little explaining
Black = Ground - i spliced and soldered mine into the other ground, both of these grounds run back out to the engine bay and ground out on the head along with any other ecu ground (get a ground kit!)
Green/Blue = 12+ key to on or start - this line will supply voltage to any tester that dosent supply its own power source. its also possible that some CONSULT cables may use it. i ran this line back across my dash and into the back of the original sohc diagnostic connector. it is located in the kick panel by the drivers side fuse box. the wire you want should be Black/Red.when your done it should look like this.
well i hope this helps someone.
Modified by moso at 9:47 PM 8/22/2009
Modified by moso at 8:07 PM 8/23/2009
