EJ20G/EJ22T harness difference?

[James614]

Okay, so I'm using the engine harness that came on my EJ20G with my stock chassis harness. Everything seems to have connected up identical to how it was previously, with the exception of this white round connector:


Considering the EJ20G has more wires running on it than the 22T (namely the extra wires for the coil packs), I found this pretty odd. I'm fairly confident that the harness on my EJ20G is complete, it looks 100% undamaged and unmolested. Anyone know what this connector is for, and if I need it on my new engine?

FWIW, the car was originally an auto and now has a 5MT, although the only AT-specific connectors I knew of were back near the firewall.

[Legacy777]

I would say there's a pretty good chance that even though the connectors plug in, the wiring is not the same. That third round plug carries all the ground pins. Subaru more than likely could have run everything through two plugs on the US cars, but due to the different models, they used the extra plugs to differentiate what models so people couldn't accidently plug the wrong engine harness into a different chassis (like you are doing )

What year EJ20G is that from? I'd suggest maybe looking at the wiring diagrams in the Liberty manual on my server and compare the engine harness wiring colors to see if they match and then compare that against the ej22t chassis harness. I think you will find that things probably don't match up.

[James614]

Hmmm, I will look at that tomorrow. If that white connector is all grounds then I probably have quite a bit more work cut out than I initially planned! Worse comes to worse then I will have to salvage the EJ22T harness, which I REALLY don't want to do as it requires modding the IACV wires, which previous posts on here tell me can be a PITA

[cj91legss]

It's not too much of a pain in the ass, however they're going to be stiff and brittle because of the heat from the turbo. Just messing with my intake manifold the other day, I moved the IAC wiring and it felt like a small twig. I thought I was going to snap it.

I have DOHC as well, so i've moved my wiring.

[James614]

I actually found a service manual for the '93-96 WRX (car my engine is from) in the service manual sticky. Nonetheless, I realized that I simply can't make sense of Subaru's wiring diagrams for determining which connector pins have which wires going through them.

But, the fact that the white round connector is full of grounds is pretty much all I need to know that I need to get my original harness back on there. What a pain... at least I already have the stuff I need to extend and protect the wires I need to change. And here I thought I might actually be able to fire it up today... silly me

[James614]

Well, turns out the harnesses are mostly identical aside from length and the different ignition systems, and aside from the purge solenoid on the 22T and a single wire connector running to the PS pump on the 20G.

The white connector in the USDM harness is completely separate from the actual engine harness. Once unwrapped you can simply wrap it in with the EJ20G harness for the same effect.

For piece of mind I depinned the longer sections I need from the 20G harness and placed them in the 22T harness. Since I didn't check every single pin between both harnesses, I shouldn't run into any surprises this way. Plus I will have a harness with fresh conduit that isn't disintegrating now.