ECU Plugs -- Wiring Details

I have been working further on the wiring for my conversion.  At first when I saw the mess of harnesses that I pulled from the donor Subaru vehicle, I thought I would farm out the wiring work.  Well, it turns out no one wanted to do it and/or no one was prepared to work on a 2001 OBDII wiring system when I started!  Guess I'll save some money on this one.

As detailed in an earlier post, I worked through the harness and identified each connector one by one and taped and wrote the plug number and system info.  I then started to windle the wiring down one wire at a time.


And ended up with a big mess of unuseful wires!


I then started detailing the wires from each of the three plugs going from the ECU out to the subsystems and captured all of the pertinent info in docs (connector number (male and female), wire color, and terminal numbers from/to each connector and subsytem each wire belongs to).  Please be advised that this information my be incorrect (tired, blurry eyes) and use it at your discretion.  Also please note that the wiring schematics are for a 2001 USA Subaru Impreza with a 2.2l N/A engine and an automatic transmission.  I am also retaining the radiator system and the A/C system and running fans and components for eac directly from the ECU.

A/C Cooler and rear heater

 First up is the rear heater.  I snagged a rear heater assembly from a salvaged Vanagon in my local salvage yard.  It was pretty dirty and I am not entirely sure that the core is good.  There was evidence that perhaps some leaking had occurred simply based on the junky gook that coated the outside of the core when I picked it up.  I suppose I could run water through it to see if it hoold, I just haven't yet.


The idea will be to place it in the rear of the bus under the Z-bed.  It will take up some space, but I'd rather have heat then an extra cubic foot of space. 

The potential negative of placing the heater assembly under the Z-Bed is that the lower access door will need to be removed and replaced by a vent of some sort, or the door itself will need to be modified.



I will also need to creat some kind of mounting system.  I am thinking about removing the orginal vent tube to route my heater lines through so I don't have to cut or drill holes in the floor.

The next step is to figure out placement of the A/C cooler.  I am considering two options: one is to mount the A/C cooler under the radiator so the airflow and dual electric fans can be used on both the A/C cooler and the radiator.  I don't know exactly how much protrusion this will create under the bus.  Once I start mocking up the air duct system for the radiator, I will take some measurements and make a decision. 

Option #2 is to mount the Subaru A/C cooler on the outside of the framerail between the rocker panel (where the propane tank usually sits).












The only problem with this approach is that it will require additional fans, relays, and wiring to the underside.  And since I don't have the additional fans, I am not sure how far down the whole system would sit below the rocker panel...  Mounting the A/C cooler under the radiator would prevent the need for that extra work.

Engine installation

With the engine and transmission mated together, it was time to roll the unit under the bus and get it bolted in!  The process actually went very smoothly.  I had to take the throttle body off to fit the unit under the bus (I lifted only the rear passenger side of the bus just enough to roll the unit under).  I had the motorcycle jack under the engine and a hydraulic floor jack under the transmission to support both ends.  Once the unit was under the bus, I lowered the rear corner and slowly started to jack up the engine first, then the transmission and continued this way until the everything was up and aligned. 

I bolted the rear (front of the bus) of the transmission first and then started working on the two bolts that attach to the upper cross member.  You can see the close fit against the fire wall after I reinstalled the reverse throttle body.  Without the reverse and in stock location, there would just be no way to squeeze an air intake pipe on the throttle body.

I had a slightly harder time getting the bolt holes to align on the upper cross bar.  After poking around, I realized that the heater pipes on the passenger side where interfering and not allowing the engine and transmission to completely lift as high as necessary ( I am not using a reversed coolant manifold; it stayed in stock orientation).  I used a cheater bar and gently, very gently, bent the top most heater pipe down just enough to allow the engine/transmission to achieve full height.  Once I did that, the bolt holes on the upper engine cross member aligned with no problem!  

I had to make one other modification to fit the engine and that was with the original airbox support bar.  In stock form, it interfered with the Subaru oil filler cap and also prevented the engine from fully sitting in the bay.  I had to bend just enough of the end up to allow the oil filler cap to fit properly.  The metal was brittle enough that as I bent it up, it just snapped off, resulting in a shorter section of the original air box support bracket.  Oops.  Non-returnable modification #1.



Everything else went on pretty smoothly.  I reconnected all of the transmission accelerator lines from the pedal assembly to the new Small Car throatytle cable set up.  Everything fit perfectly. 

Because of the reversed throttle body set up, my accelerator cable in stock form is slightly too far forward and ends up sitting almost exactly below the housing.  I think it will work in this arrangement, but I may try to move the cable retaining clip further toward the rear of the bus to give a better arc from the end of the cable housing to the throttle assembly (so the upperward bend isn't so sharp).  I think this will be easily achieved be taking the cable retaining clip and simply flipping it 180 degrees...I may loose my spark plug wire holder clip, but oh well.

Next up is getting the rear cross bar modified to fit.  I am using the Small Car engine mount system and purchased the two inner and two outer rubber mounts.  This set up is intended for a Vanagon install, so either a custom cross bar needs to be created to fit, or a Vanagon cross bar modified to fit.  I choose to go the latter route.



I found a Vangaon rear engine cross bar at my local slavage yard for pretty cheap.  The first thing that had to be done was to cut out the orginal framerail brackets since they were too tall (didn't allow the bolt holes on the bar to align with the rubber mounts) and too wide (the frame rail distance apart is different on a Bay versus a Vanagon.













Once I had the framerail brackets off, I test fitted again and realized the bar is still a bit too tall to fit, meaning the top of the engine cross bar hits the bottom of the frame rail before the bolt holes fully align.  It is off only by a 1/4 inch at most.  I marked up the location and width of the frame rail on each side of the engine cross bar and will have to cut the end off and recess the top of the bar a 1/4 of an inch plus the thickness of a steel plat that will be fabricated to mount to the bottom and wrap up the outside of the framerails.  I haven't gotten to that point yet but hopefully will shortly after the holidays.  I'll try to take some exact measurements and post those for any interested.



Next up is the radiator placement and duct work, the fitment of a rear (Vanagon) heater asembly, and the A/C cooler and system install.