I have had a few people been asking about my wiring. Its just the way I did it, i am not liable if it doesn't work out for you.
This is for the gauges. Simply tap what you want and run it to desired gauge.
(My truck, i didn't use any of these wires.)
These wires are located by the ECU, and are usually white or brown plug. The way I wired my truck, i didn't use any of these wires, just thought they would be helpful to some.
Here is what you will be looking for, for above wire colors. Usually a white or brown flat plug. S13 Nissan 240sx guys use the term, "Dash interface plug" IGNORE THE WIRE COLORS IN PICTURES.
Brown is a DOHC chassis dash interface
White is a SOHC chassis dash interface
First Step 1.
Now, you have a 3 pin O2 sensor plug, it needs to be extended about 4 inches on either side (you choose) This plug will have a BROWN/Yellow, BROWN, and WHITE wire.
Here is what the O2 sensor wire looks like.
Second Step 2.
You will need to extend the MAF wire. This will have a shield loom signal wires (2) dont be scared of that. Find a nissan 240sx OEM harness and cut the MAF wires from it (or any 2 wire shielded MAF wire from any car really) There will be 3 wires, Black, white, and black white stripe, just extend them 3ft, yes, 3ft. So the maf wire can run across the fire wall and around to the driver front of the truck.
SR WIRE COLOR FUNCTION
Black / White +12V (Power)
Black MAF Ground
White MAF Signal
I used a Z32 maf sensor.
FOR Z32 MAF USERS, THE PINOUT IS: (ECU retune is required)
Third Step 3.
Cut and put power where it needs to go into the OEM sr harness. No need to cut open the harness, etc etc. Just cut the power interface pigtail off. Here is what the power interface plug looks like. (See Figure 1a. below) Now that you have cut the pigtail off, you will see a few wires you need to run the sr20det in your truck, Thick blue/red stripe, Thick Black/Red stripe, Red, brown, black/yellow stripe, Black/White stripe, red/black stripe See figure 1b. You don't need any other colors! You will need to wire in 2 or 3 Relays in the location of the passenger side/center cab of truck.. I can't explain how to wire in a relay, but i am sure you can figure it out.
SR Wire Color
ECU Relay --- Red / Black stripe 12v Switch Power --- Wire to Relay 1 12v Switched
ECU Power ---Black / White stripe 12v Switched Power ---Wire to Relay 1 12v Switched
ECU backup power --- Red 12v Switched Power Relay 1 12v switched
Main ignition power
Black / Red Blue / Red Connect Wires together. 12v switched/Relay 2 12v Switched
Brown Any +12V Switched O2 sensor power
Black / Yellow stripe Any +12V Switched Idle air control solenoid power
Black / Pink stripe Not Used. Fuel pump relay
Green / Orange stripe Not Used. Transmission neutral switch
Green / Yellow stripe Not Used. AC relay
Blue / Green stripe Not Used. AC relay
Here is the "Relay panel i fabricated up" You can do it how ever you wish, just make sure they are FUSED, and have power supply off a relay.
ROUTING IN THE ENGINE BAY
(Update later with pictures of the routing i choose)
Requires cutting hole bigger and some sort of rubber grommets to prevent the sheet metal from rubbing threw the harness on fire wall. Runs as it would in the Nissan 240sx, ecu mounts to the kick panel of truck, and the power interface wires run any where into cab you wish, i ran mine to the center console.
Tap and drill OEM water neck for sending unit. Then run wire to your gauge of your choice.
You will find that the oem dash interface wire WILL not output a aftermarket gauge signal wire. (It did this for me anyways)
You will need to TAP PIN number 30
I haven't got to the Speedometer as of right now.
NOW! YOU HAVE A UPPER HARNESS THAT WILL RUN THE SR20DET!
*****I will brush up on the LOWER harness later on.******
Its pretty Simple.
Remove thick starter wire, and loom back up.
Plug in the OEM sr20 lower harness into the trucks OEM harness.
1. Starter wire, just plug trucks starter wire into sr pigtail sr lower harness, no need to cut open lower harness, just tap what you want off the sr pigtails.
2. Alternator, Thick (+) Terminal to starter (+) Terminal. Then just 12v switch the white with red stripe wire.