Spec R

Who's done one?

EDIT: this is for my 99 Subaru Impreza RS, with a 2002 WRX EJ205 motor.

Why is this on a honda forum? because a lot of guys here now own Subaru's.

Spec R

yep. its pretty wild. it happens when a seasoned mechanic is told "get the car running no matter what, but as safely and quickly as possible" before wrx motor swaps were common place.

the car basically has 2 wiring harnesses co-existing where there should only be one. Given the state of the connectors and the fact that i was getting all sorts of funny readings from random sensors, not to mention being left stranded (the final straw). I decided it was time to replace this harness.

Its become a huge project ( in my eyes). So far I've had to:

-hunt down a 99 RS bulkhead harness
-hunt down a 02-03 WRX bulkhead harness and bulkhead to engine harness
-Find someone to do the harness merge. Gotta leave that to the pro's. I was referred to Brian Keene aka I-Wire from a fellow RS owner at a local shop.
-Take apart the entire interior, down to the dashboard and everything underneath it.

-WRX harness in a box


-Brian came over and started to do some diagnostics on the car and we concluded that regardless of what caused the car to stop running correctly, we need to swap the harness out. He took out most of the dash and console in about 1 hour taking his time, that's why I have no pics.

I decide, If I'm going to do this, I might as well fix everything else related, like the stereo wiring and stereo setup, along with the alarm.

I started gutting the car.


Ghetto amp mounts and massive amounts of poorly routed wire.


extra speed sensor plugs (more butt connectors)


non existent wrx cruise control

Spec R

jump a couple weeks of waiting to hunt down harness and such (i let the car sit for a bit)
and I finally start to really take apart the dash.

after struggling with tamper resistant SRS plugs, I finally got the dash bar out. You have to support the steering wheel with a jackstand so the column doesnt collapse on itself. Brian said, its not worth your while to remove it. So it stayed in.


oh the humanity.



a reason why I gutted the car completely was to look for this box. its the wrx fuel pump controller. apparently when the harness was made, the recepient plug wasnt available. so what did they do? they cut the plastic, and soldered directly to contacts.




Blower motor out. At this point, you have to disconnect the AC lines. You have to pull out the intercooler/bov to gain access to the lines and other stuff too. You also have to take out the heater core and the associated coolant lines.

Intercooler out - older pic for reference

Spec R

heater core out...revealing more butt connectors


a whole section of unused wire, just hanging out


a closeup of where the bulkhead harness meets the body harness. this was supposed to be a plug and play affair with the new merged harness, but that would have been too easy.





Thats pretty much where I'm at now. I didnt want to dig further without the new harness in place, which I now have.

Spec R

car has random CEL's from time to time. a couple months ago, i get 2 CEL's at the same time, and the car shuts off in the middle of the road. I decide (w the help of some more experienced Subaru guys) that its the harness and its numerous butt connectors causing the issues. If not, at least we can rule out the harness.

believe me i'm taking my sweet ass time w this. its been a couple months already. :wtc:

inorite? i'm not even doing the hard parts (the merging) and I'm still wtf. :screwy:

Civic2Scooby

hey, that looks familiar h:

M@rshy

Holy hell. My hat is off to you. When do you expect to be done?

Spec R

i dont kno when i'll be done. its really hard to do work on the car since its been so hot, but i expect to get a lot done this weekend.

my first goal is to get the new harness in and get the car running again. then after everything checks out, start doing the stereo, alarm, a/c, etc. those involve their own stuff too. i have to buy new RCA cables, A/C drier, shift boot, arm rest, and some other stuff.

Spec R

continuing from above...

lets get that harness cleaned up. so they used butt connectors on the chassis side of the harness, and left very little usable wire where they cut the wires from the plugs.





6 wires


1 wire


3 wires


the 6 wires from this plug had to be lengthened by about 10 inches, so thats 12 soldered connections



this brown wire had to be lengthened also.


these three wires had to be de-pinned to be soldered. even then, they gave me a hard time. I put tape over the shrink wrap just to be safe.

Spec R

the complete merged harness a la I-Wire


made some progress this morning - basically got most of the engine compartment out, except for the SMJ portion.


this part really shows the space that two harnesses are sharing