So I have a 89 JDM B16a that iv been swapping into 97 ex civic for a while now. Everything has been hooking up fine so far until I got to the electrical part. I know that the motor came originally obd0 and my car is obd2a. So I switched the intake manifold, injectors, throttle body, and distributor all to 99-00si. I also have changed my alternator to a 96-00 obd2 and have a 99-00si Vtec pressure switch/solenoid coming in the mail. Sadly I never had a wire harness due to previous from the previous owner taking it and I need help with figuring out what wire harness can fit my engine swap but still be used in my car. If someone could please help me figure out all this confusing electrical bullsh*t Id be grateful.

 

This is what I posted to your query in the other thread... and thanks for making your own thread, as well as providing more specific information.

"You use the engine harness that came with your car... and if you don't have it, GET ONE just like the one that should have come in your car. Then, modify it to fit the new engine... lengthening or shortening wiring and changing plug types as necessary. You didn't feel it was necessary to provide ANY information about your chassis or the year/model "B" series swap, so I cannot be more specific."

This means you need a '97 Civic EX engine harness... and if you get an automatic harness (4 ECU plugs and the green crossover plug), you can use one of those extra wires for your Knock sensor.

 

So what specific information do you need??

Your saying I should I go and get a d16y8 engine harness, that’s manual, and it will plug up to my 99-00si intake, dizzy, injectors, etc.? Or do I have to buy all the plugs and rewire them myself?

 

Yes, you will need a '96-98 Civic EX engine harness. A manual one will provide all of the necessary plugs that you will need to use on the B assuming you have all OBD-2 type parts (alternator, injectors, IAT, dizzy). You may have to lengthen or shorten some of these plugs, but no issues. You will have to run a single wire through the firewall for your knock sensor since you are using a '99-00 Civic Si ECU. You will also need an OBD-2A -> OBD2B ECU adapter harness so that you can plug your ECU right in.
If you get a '96-98 Civic EX automatic engine harness, you will have a bunch of extra plugs that are not needed in the engine bay, and you can convert one of these wires to the knock sensor and not have to run a lone wire through the firewall. You will also have to convert the 3-wire IACV to a 2-wire plug, but otherwise it will be pretty basic. You will still need the ECU adapter harness. Your call.

 

Ok that’s good to know, so my motor is out of an 89 crx and used to be obd0 but I changed it to obd2b being (IM, throttle body, injectors, alternator, and dizzy) and I have a JDM p30 ecu and it’s obd1. Will that still still work on my car and motor, or do I have to run a 99si ecu?
Second, I thought I needed 99-00si engine harness to use obd2b parts not the obd2a engine harness.
My last question is because my motor is noe obd2b is there anything else I need to change so that everything is the same OBD?

Sorry if these are stupid questions, this engine swap and wiring is all new to me and I want to make sure I don’t miss any small details or have waste my money and time on unnecessary stuff.

 

 

Ok sweet. So do you know what sensors won’t be used if I do use a p30 ecu?

My last question is do you know what specific sensors or plugs I won’t be using on the automatic wire harness in general?

 

Everything on the transmission portion of the engine harness EXCEPT the VSS, and the reverse lights would need to be wired using a pair of wires that runs into the passenger compartment and terminate at the ECU plugs so that you can extend those to the green crossover plug so that they work.