At the start of last year I did a post about how I'd like to revamp the entire wiring harness as it hasn't really been touched since doing the motorswap/EFI conversion 6 or so years ago, and has had a few things tacked into it since for the dash. It was never the prettiest conversion in come spots, one contributing factor to this was just pulling back the ED shock tower plugs and leaving them here, and the ECU harness being too long as I didn't want to repin everything, so again things were pulled back inside and bunched up.

Happy to say I've actually had no issues with the EFI conversion ever! Just not the cleanest execution, but I always knew I wanted to redo this one day.

With respraying the engine bay now, I pulled back through the engine harness, the OEM strut tower plugs were already inside the cabin. As you can see from the photos below it turned into quite a mess. With this I decided maybe now is the time for the full rewire.

Everything follows the OEM layout currently, ECU in the passenger footwell, fuse box up underneath the dash to the right of the steering column. The AC blower/heater unit harness still exists but have been cable tied back as you can see, including the ED D15B4 carby ECU plugs. I'd love to remove all of the harnesses which aren't being used.

As you'll see the further we go, I ran out of time trying to get everything done due to injuring my back, which put me out for 3-4 weeks, so in the end no wiring got revamped. I think the best approach to this as well would be to get a complete loom for my car and do it as a project on the side, just so the Civic is always running. I also wanted to bring hte strut tower fuse box underneath the dash to clean up the engine bay, and move the fuses away from the heat.

This is the messy section, in the grey duct taped section to the left is where I connected various wires from the ED cabin harness to the DA OBD1 harness which laid over the cabin loom from ECU to engine. The original ED strut tower plugs were pulled back inside of here as well as you can see one dangling in the middle.

All cleared out! So empty! The battery positive 2 gauge wire was never really secured, looped through various brackets on the firewall. Should probably look to mount this correctly as well.

And heres most of the harness, laid out how it would be in the car. From left to right, it's the engine side, then comes back into the cabin with the loom running from ECU on passenger side across to fuse box on drives side. The rear harness for fuel pump and tail lights was left in the car.

In the future I'd like the rewiring to route it only through 1 hole on the firewall, currently coming through the 2 factory holes.

Wing harness

During the EFI conversion I re-routed the headlight/radiator fan harness through the fenders to clean up the bay. I did this by cutting the wires in the middle, plugging them in on the front end and then soldering in wire extensions between the two. I routed it through a grommet where the front doors bolt to the chassis, I think it would normally be a sunroof drain plug.

Again, no issues, but could be improved. The issue though was because I routed them through a small hole the size of the conduit, the headlight plugs wouldn't fit back through. With the idea of redoing the whole wiring, I cut the tucked harnesses in the middle, labelling the wires each side of the cut matching numbers for later on.

Had to peel back all the tape that was used, was quite a messy job with everything being so sticky. Found a few dodgy solders and heat shrink jobs I did at the time.

Heater removal:

Since doing the motorswap I left the heater box in the car with the intention I'd need it to demist the window. The issue at the time was, I couldn't get the metal cables for the hand controls to work correctly, so I was never able to actually turn it on from inside the car.

With not having this on the road anymore, and having removed the hand control unit last year, it was time to remove the heater unit. It along with the coolant hoses weighed 3.7kg! Obviously would of been a bit more with the coolant running through it. I've never cared that much about weight saving, but it was good to see this.

I have some rain-x product on the windscreen which helps it not fog up, and I've never really had an issue either. Worst case I'll get some sort of motorsport heating unit you see on the top end GT cars. Much cleaner under the dash without it too!

Additional bs

When removing the steering rack at the start of today, the boss kit was stuck on the split and I couldn't get it off regardless of what I tried. I grabbed a rubber mallet and tried hitting the wheel from behind. In doing so, I accidentially swung back a bit too far (not that there was much room to do so anyways) and managed to hit the indicator stalk on the instrument body, snapping it with bits of plastic flying everywhere. Luckily I have like 4 spares of these, but still..