1974 Mini with B18B, need wiring help...

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So I bought a 74 Mini that a guy had started converting to Honda power with a B18B motor. I started on the wiring today. I have schematics for the OBD2 ECU (according to the PO the motor was from a 97 LS Integra). I was given two engine harnesses and a Chassis harness. The Chassis harness was labeled as a 98 Integra Automatic, but the engine harnesses were not labeled. By searching around I determined that one engine harness was a GSR harness. The other harness in not known. I have an alternator that came with the car that matches the GSR engine harness. The alternator plug does not match the other engine harness.

Today I sorted out the wiring on the ECU and cut out what I don't need for the swap. But I am wondering if it will be ok to run the GSR engine harness with the Auto LS chassis harness and ECU? Obviously I am going to have extra plugs for the knock sensor and VTEC switch and solenoid that I am not using. Will I throw codes and MIL lights if they are not hooked up?

I am new to the world of Honda Swaps but I have worked on EFI wiring in the past during other swaps.

Also at the end of the GSR Engine Harness (Drivers side, Opposite of the incoming wires from the ECU) there are three plugs? Where do those plugs terminate? Are they for A/C or Power Steering? I figure I will just leave them unplugged and not cut them at this point.

I am sure I will have more questions at some point so thanks in advance for your help.

You won't throw codes so long as you are using the ecu for the LS motor. Are the three plugs you are referring to capped? If so, don't touch them. They are for the optional accessories, however, those plugs have joint connector caps, so they are also running some circuits that are nececary.
Thanks for the input. One of the three plugs is capped. The other two may have been at one point in time. I am sure the harness was messed with at some point in it's life.
So how do you ask questions about a Honda swapped Mini and not show us pics? Haha.
Well, right now it just looks like a Mini shell. Nothing special. I will post up some pics in a few weeks when the motor is in.

Is there a way to reprogram the ECU to get rid of the EVAP sensors and a few other things I wont be needing... or is it more trouble than its worth and just run a EVAP canister?
This is pretty cool. I'm subscribing in hopes that you'll post pictures sooner rather than later. Even if it's just a mini shell.
I am going to post a build diary on a mini site today... I will put up a link when I get one.
ECU's can be chipped, but generally not obd2 ones. At least not easily. most folks with obd2 cars convert to obd1. you can use a p75 from an obd1 ls teg pretty easily on that motor with a conversion harness from a place like rywire.com