Alex Preece

Hey everyone! Just finished my OBD2 B16A2 swap into my 94 civic. I used an obd1 wiring harness off the original d15b7. On the b16 came an alternator that has a flat 3-wire plug on it. My wiring harness has 4 wires that go to the plug on the alt. I did some research and found this:
OBD1 — OBD2 plug
blue to white/red
black/yellow to black/yellow
white/blue to white/blue
white/yellow to white/green
However this is for the square plug after I did some research. My plug is only 3 wires and doesn't have the white/green wire coming off it. So I wired everything up and I'm left with the white/yellow wire on the harness which I believe is for Alternator control. I let the car run and pull the negative off the battery and the car instantly dies. I also tried mounting my d series alternator onto the b16 in numerous ways with both brackets and no luck. Has anyone ran into this issue?

JRCivic1

Your test is flawed... this is not a carbureted engine. The battery powers the ECU, so when you disconnect it, the ECU goes dead and thus, the engine follows. I am not sure what market you are located in nor where such an alternator would be offered, but in the US, Canada and Japan, "B" series alternators would all have a 4 wire plug socket... even if all wires are not used in a particular application. The black/yellow ELD wire is omitted in some markets. This is not your issue. I suspect your best solution will be to get another alternator from a local salvage yard (or better yet, spring for a Honda re-man unit) that matches your OBD-1 style plug and move on.