Unlike in some cars such as VW’s, in a Subaru, the engine management wiring is not conveniently in a separate wiring harness which you can just take out and use in another car with minimal modification. The wiring in a Subaru is split up by location in the vehicle, not by function, and this means that to make the Subaru engine run outside of the rest of the Subaru, some work is involved to make an ‘engine management only’ harness from multiple much larger Subaru harnesses.
Price: from £283.33 GBP +VAT (£340)
Options – ft ext, fuel pump harness, lambda harness, new VW connectors, bulkhead grommet, immobiliser antenna
harness wrapping spec
Having the engine management wiring work done properly, by someone who knows what they are doing is the one main thing which has the biggest effect on how successfully your Subaru engine will run in your VW. The cost difference between having it done properly and having it done badly is typically not big in the scheme of things (in some cases it will be cheaper to have it done properly – if you do your homework on who to have do the work up front). Why cut corners here? You’ll likely regret it later – we know this as we are where unsatisfied customer of others’ wiring work eventually end up phoning when they finally do their research into who actually understands this stuff well.
We can usually turn harnesses around withing 1 to 6 weeks depending on workload. Typically, it averages around 3 weeks.
Harness work options:
All of our Subaru engine management wiring work options are designed to either make the wiring easier to install into VW’s, or as replacements for VW or Subaru standard parts which are either often missing or were not in all models, but make installation easier.
Front Extension Harness
Price: from £62.50 GBP +VAT (£75)
We developed the front extension harness to extend all of the features which have to be or should be in the front of a rear engined VW from the engine management in the rear when it became apparent that most customers were not happy with extending these to the front themselves.
Front extension harnesses are not a product which can be purchased separately – they are only available at the time we do your engine management wiring work because this includes fitting the necessary connectors for them to plug into. We make front extension harnesses for the following VW models:
- T25 / T3 / Vanagon
- Split screen bus
- Bay window bus
Depending on the spec of the conversion they extend the following features to the front:
- Engine check light
- Immobiliser light
- Vehicle speed sensor
- Rev counter signal
- Radiator fan control
- Fuel pump
- Temperature gauge signal
Almost every customer goes for this option – it’s incredibly good value, especially given how expensive the multicore cable they’re made from now is.
New VW Connectors on you Subaru Engine Mangement Harness
Price: £29.17 GBP +VAT (£35)
This option is a set of things which makes the Subaru engine management plug in to the VW connectors in watercooled T25 / T3 / Vanagon models. You’ll probably think the low price is a mistake – it isn’t. More info on that later. It includes:
- Fitting all the right VW connectors (of the 12 possible combinations) to plug in in your engine compartment junction box.
- Fitting the correct low coolant level sensor connector to suit your VW and the wiring to it so the low coolant level system works as exactly as VW intended.
- Wrapping the harness in tape and conduit to OEM specs. This is only viable once the exact routing of the harness in the VW is determined, and for the water cooled models where the engine management plugs in to standard VW connectors, the exact routing isn’t defined until all the relevant VW connectors are fitted. If you don’t go for this option, the harness tape and conduit are supplied loose, for you to fit once you’ve determined the exact routing.
- Bespoke bulkhead grommet fitted to the harness (fits into a 52 x 90mm slot with full radius ends)
- Coolant temperature sensor extension cable for conversions using a reversed coolant manifold.
No used parts from your VW wiring needed – we use all new connectors where the wiring plugs into the VW. There are a couple of reasons why this option is so inexpensive. Firstly we source the connectors required much more cheaply than anyone else doing similar work is likely to. Secondly, in our opinion, this option combined with a front extension harness is the right way to install Subaru engine management into the water cooled VW models – plug and play with no modifications to the VW wiring, and we want to encourage all customers to go for it. This works – almost every customer goes for this option.
Only available as an option with our harness work – we don’t sell the individual parts used individually.
Fuel Pump Harness
Price: £10 GBP +VAT (£12)
Late model fuel injected T25 / T3 / Vagagons (1987 –>) had a separate harness for their fuel pumps. This ran from the RH front corner of the engine compartment in 2wd models to the pump, or from the engine compartment junction box to the pump in Syncros. Initially we just stocked the VW connector so we could fit it to the Subaru engine management harnesses and the original VW fuel pump harnesses could plug in, but then realised it made sense to offer a reproduction of those harnesses too as they’re a neat way to withe the pumps in earlier or non injected models which didn’t originally have them.
Fuel pump harnesses are not a product which can be purchased separately – they are only available at the time we do your engine management wiring work because this includes fitting the necessary connectors for them to plug into.
You need to specify whether you are using a ring or a spade terminal fuel pump when ordering.
Rev Counter Interface – built into your wiring harness when we do your harness work
Price £30.00 GBP +VAT (£36.00)
See Rev Counter Interface for more details
Subaru Cruise Control
Price: from £133.33 GBP +VAT (£160)
If your donor car had factory fitted cruise control, it can be used in your VW if you want it. We can only add it at the time we do your engine management wiring work, or if you send the engine management hardware back to us at a later date (so we can install the necessary fuse, wiring and connector). Includes all parts to mount the cruise control hardware.
See Subaru Cruise Control
Lambda / Oxygen / O2 Sensor Extension Harnesses
Through the Subaru engine management harness, the low level lambda / oxygen / O2 wiring uses screened cable to keep out interference from other nearby circuits. Also, the wires on the lambda sensor itself are not copper, so are not easily soldered. Both of these make extending the wiring to the lambda sensor, if required by your exhaust routing, difficult. Also, because the signals are very low level, they are more prone to stray resistance from dodgy connections (such as trying to solder to the non copper wires). The best way to extend the lambda sensor wiring if required is via a plug in ‘extension lead’.
We stock the new connectors to make extension cabled for almost all of the (many) Subaru lambda sensors. These are not ‘off the shelf’ products – they’re made to order for each customer. You have to tell us how long you need the extension cable to be.
Replacement Subaru Lambda / Oxygen / O2 Sensor Adaptor Harnesses
Various Subaru models use short adaptor harnesses between the main engine management harness and the sensor(s). These are sometimes missing when customers buy the parts from a donor car – usually because that car was in a breakers yard, and they’d already removed the catalytic converter(s) to sell them, leaving the sensors and adaptor harness attached to the cats. These are the genuine Subaru parts that our reproductions replace:
The lambda adaptor harnesses can be custom made to non standard lengths if you would have also needed a lambda extension harness.
Price: £50 GBP +VAT (£60)
If you have the MY00 onwards engine with the Mitsubishi immobiliser, but don’t have, or don’t want to use the key and lock barrel assembly in your conversion project, we make a new immobiliser antenna which reads the transponder chip without the key body or ignition lock barrel being present. These are far smaller and neater then using the key and ignition lock barrel, but are not suitable for use when you want to use the immobiliser to immobilise your VW. Originally designed for customers who do not have the key body or ignition lock barrel – just the ECU, immobiliser ECU and transponder chip:
Transponder chip and immobiliser ECU not included. Only available as an option with our harness work – not sold individually.