B-Series Wiring

B-Series Non-Vtec wiring using the stock 85-87 Si Engine Harness
by DEIVIONCRX

I had several harnesses lying around including a 90-91 Teg, 90 DX CRX, and 2 87 Si’s, so I had plenty of wire and connectors to pick from, you might need to hit the junk yard to find some connectors and wiring.

You will need Wire cutters, De-pinning tool, Solder, Heat shrink tubing, Soldering iron, electrical tape and possibly a few other tools.

Connectors Needed
2 Wire, Round IACV connector, Blue/Yellow, Black/Yellow
Multi-Wire Distributor Connectors, OBD0, or OBD1
88+ TPS Connector
2-4 Pin Connector Male and Female
6-8 Pin Connector Male and Female

Wire Needed (Enough to go from Sensors to the ECU)
2 Wire, Shielded Wire, Orange and White if OBD0, Blue/Yellow and Blue/Green if OBD1
Blue/Yellow
Yellow/Green
Black/Yellow
Black/Yellow (Large gauge)
Blue
Brown/Black

Start off by stripping all the electrical tape and conduit off the harnesses you are going to use, as I pulled tape off, I went back and did one wrap around wires to hold the general shape so it would still fit pretty much like stock after I’m done.

Once you have everything unwrapped, you can start adding connectors where they need to go, Add the IACV connector and wiring to the bundle of wires that lead to the Oil Pressure Sensor and Alternator, you might have to hang the harness on the block to get the right amount of length, put a wrap of tape around where the IACV wires will enter the harness, leave the wires hanging you can extend them later to the Main Engine connector. To get power for the IACV run the black/yellow wire over to the yellow/black wire that powers the injectors, it comes out of the small 6 wire plug on the driver side strut tower and goes into the resistor box plug, just cut the insulation back on the yellow/black and add the black/yellow wire to it, solder it in place then heat shrink and tape everything back up.

Next you can cut off the existing distributor connector, and solder on the new one, matching the colors that are there, you will have to add the Crank Angle Sensor(CKP), use the 2 Wire Shielded wire for this,(this is where I got confused with my build because I am using a OBD1 distributor) the stock Si harness uses orange and white shielded wires for the Cylinder Sensor(CYP), but the 88-91 ECU uses Blue/Yellow and Blue/Green, while the OBD1 distributor uses the Blue/yellow and blue/green for the Crank Angle Sensor(CKP)) once you get that figured out you can solder the Crank Angle sensors wires to the Shielded wire combo then tape it back down to the Main Engine Connector, you will have to take the shielding ground wire(silver twisted wire) and add it to the ECU Brown/Black ground wire that bolts to the Thermostat housing.

To switch the TPS Connector from the 85-87 to the 88+ style plug you can just de-pin the stock flat 3 plug and plug the wires into the 88+ Style plug they are the same style pins, With the Tab/Lock Clip facing away from you the order is Yellow(Power), Red(Signal), Brown(Ground).

To add the RPM Signal and Coil Power Wire’s you will need to solder the large gauge Black/Yellow wire to the Coil power wire at the distributor and the Blue wire to the Blue wire coming from the Distributor; I ran these wires down the harness across with the injectors over by the Resistor Box Plug.

You will have one wire left on the Distributor plug and this will be the ICM (Igniter) wire, take the Yellow/Green wire and solder it to the Distributor plug and run it down the harness over to the Main Engine Harness Connectors.

This should have all the sensors needed to run the Engine, you will not need to add the wiring for the Coolant Temperature Switch because the Radiator for the 85-87 Si’s has it in it and wired already, and everything else on the harness will plug into the B-Series Motor and the existing 85-87 Si.

Now with the wires left hanging on the sides of the engine harness, this is where the 2-4 and 6-8 pin connectors come in, I used the 6-8 on the Passenger side strut tower, and connected the ICM wire(Yellow/Green), IACV signal(Blue/Yellow), Crank Angle Sensor(Orange & White, or Blue/Yellow & Blue/Green), run all of these wires into one side of the connector, then use the other side to match the remaining wire and run the wires down to the ECU and pin them into the appropriate spots on the ECU(For these pinouts, look at the B-series Wiring Chart in the Wiki).

Do the same with the Blue and Black/Yellow wire on the Drivers Side but you will have to cut off the pre existing connector that goes from the coil into the car, just match colors and use the 2-4 pin connector.

After you get everything nice and neat, every wire ends at some connector, you can go back and tape the harness up and add conduit as you see fit. Now you have a fully functioning Harness that plugs in to the factory 85-87 Si with only 2 extra connectors to worry about.

I have done all of the wiring but I do not have the engine in the car, in my mind and theory it should work fine but if it does not I will fix this write up when the motor does go into the car.

If you want to add Vtec, all you need to do is get the appropriate Vtec connectors and wiring, and add them the same way you did the distributor wiring.

Unwraped Harness 95% finnished [img]http://www.redpepperracing.com/gallery/d/174796-1/Harness6.jpg[/img]
Wraped harness Finnished
[img]http://www.redpepperracing.com/gallery/d/174799-1/Harness1.jpg[/img]
CKP, IACV, and Ignitor Wires added in a sub-harness leading to ECU [img]http://www.redpepperracing.com/gallery/d/174802-1/Harness2.jpg[/img]
IACV Plug Add'ed
[img]http://www.redpepperracing.com/gallery/d/174805-1/Harness3.jpg[/img]
TPS Plug swaped, and OBD1 Distrubitor Plugs Add'ed [img]http://www.redpepperracing.com/gallery/d/174808-1/Harness4.jpg[/img]
RPM Signal and Coil Power Wires Add'ed [img]http://www.redpepperracing.com/gallery/d/174811-1/Harness5.jpg[/img]
CKP,Ignitor,IACV Subharness Installed [img]http://www.redpepperracing.com/gallery/d/176598-1/Civic39.jpg[/img]
[img]http://www.redpepperracing.com/gallery/d/176601-1/Civic40.jpg[/img]