B18b1 wiring harness


New Member
Hello, all. I have an OBD2 B18b1, I am swapping into OBD1, 95 civic. I am planning on staying OBD1 and have a P75 ecu. My question is this...which engine wiring harness should I use, the civic or the Integra? I've searched and read and seem to find conflicting answers. Can I use the harness from the D15b7? and if so what modifications will be necessary? The harness I got with the B18 has been hacked up. Whats the easiest way to do this swap without buying pre-fab harness.
As Brian said, yes, you use the civics harness. Just label them all before taking them off, or get the service manual from hondahookup.

You will need to change the IAC plug on the civics harness to the 2 wire plug of the b18s IACV on the back of the intake, which involves the change of wiring at the ecu as well. You will need to lengthen the TPS 3 wire plug by about 8 inches to reach the b18b throttle body from the injector part of the harness. I also had to lengthen the single wire lead to the oil pressure sender, and I made a male to female extension pigtail to reach the b18s o2 sensor plug on the back of the block.

To get the tach working, the easiest route is the obd1 dizzy option. Obd2 pulls the signal from the ecu, obd1 takes the signal from the dizzy of course, as Brian would know, hence his suggestion.

Im not positive about the internals of the d15 dizzy, but Im sure they are the same as the d16 internal parts, as in the ICM, coil, CYP, TDC, and other sponsor in the dizzy are the same as the b series internals, and the D parts can be swapped into the b dizzy housing.

Also, since you have both an obd1 and obd2 dizzy, you can also make an adaptor pigtail to run either obd dizzy. I can take some pics of mine later and give you a rundown of how to wire it if you would like. I just finished a similar swap myself, except the opposite direction. Obd1 94 ls engine in a 2000 civic dx chassis. I also did the auto to manual swap in it.