Hi, I recently swapped the engine in my 1992 Civic to a JDM D15B with individual coil packs, and I kept only the engine harness connected directly to the ECU. The harness that runs from inside the car to the engine bay is left disconnected, so now I don't have an OBD connector. I want to add a 3-pin OBD1 connector; I bought it, but I'm not sure where to find the information or diagrams to splice the wires and install the connector. Can anyone guide me or know someone who has done this before?"

 

In the manuals it's called a DLC (Data Link Connector). In the factory harness, the center pin is always hot. I re-pined mine to Accessory power instead. That way my Hondash Bluetooth unit wasn't always on, draining the battery.
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One outside Pin goes straight to D7 on the ECU, the center pin should be accessory power, and the other outside Pin is ground. These photos are specifically a 1994 Civic shop manual.










​​​​​​BTW: Easiest way to get accessory power is a simple female spade connector pushed onto the #5 "Option" plug in the under dash fuse box.

 

Side question...... How do you like the Hondash? It was just being developed last I was following and I suspect it's matured much since. Wondering how it is now a days.

 

I've had it for years. It's pretty great. I was surprised it worked with my stock JDM P73-013 ECU. I rarely attach my phone to it, but it's nice to know it's there. And after modding my DLC with accessory power, it's extra nice not having to plug it in and unplug it for EVERY drive.

What's interesting is whenever your phone is attached, it datalogs everything for every sensor, for every drive in one long sequence. Because of that I noticed how much the intake heat soaks every time you stop somewhere and shut off the car (IAT sensor). Pretty neat.

I don't use it all that much. I would use it more if I could make some kinda phone mount behind my steering wheel. Maybe a cool send-cut-send project.