How to modify VT 304 Sequential V8 harness for HQ-WB

[Cleaver]

Hello chip legends,
Have been running various search keywords on the forum to attempt to find a wiring diagram / pinout guide on how to modify a VT 304 V8 harness to install the sequential iron lion and 4L60E into a HQ - WB Holden.

Does anyone have a link to a topic or can provide further info to assist?

A little hard to justify the $800 - $1100 asking price for an 8 wire connect harness.

Appreciate the feedback.

[Dylan]

ECU pin out will be the same as a VS3.
Just the wires will be in a different spot.

VS engine look connects in the engine bay near the battery.
VT is up on the passenger firewall.

It's honestly a very easy job if your brave enough to tackle it.
Post away on here and you'll get help as you go.

Lay the loom out and post a quality pic and that'll get you started.

[Cleaver]

Thanks for your response Dylan, keen as to learn and dive in to get it done..

[Cleaver]

Another pic from another camera..

[brindo]

Those conversion looms will generally have a predetermined place to mount things, so if doing this yourself you get to choose what goes where.
So the first step is working out where you want to put everything. The PCM can go up near the lh kick panel, or above the glove box. In a pinch, it can go in front of the centre console, but with any option you still need to hole saw the fire wall to get the cables through. So you need to work out where this hole will be.
Ignition module needs to go somewhere. On a VT, the wiring to this is a bit longer and is mounted on the air cleaner base. But find where you think is best to fit it in the HQ-WB engine bay.
There will also be a bank of relays and fuses for fuel pump, PCM, thermo fans etc, so figure out where you want these too.
Being sequential, you will have MAF, so assuming you are running the factory manifold. So the air cleaner needs to go where the battery would sit unless you run a pod. So you may choose to relocate the battery to the drivers side or to the boot. But you need to decide upon this as you need to take a power source for relays. You can also source power from the starter motor positive, or from a battery isolator if you plan on running one.
Other than that, the location of all the connectors on the engine will pretty much stay the same, but be a good idea to extend the wiring to the ignition coil so it can be mounted somewhere more sensible than where the factory put it.
But if you can plan out where you want everything first will save you drilling too many holes than are necessary.

[Cleaver]

Thanks Brindo, great points to mention..

For this particular conversion, the aim is for a clean "As factory intended" installation.
The battery will be relocated from the HQ-WB location of LH Front to RH Front.
The PCM will be located in the Passenger kick-panel area.
VT V8 Airbox will be used and installed into the LH front, utilising the MAF and Air Temp inputs.
Ignition Module will be mounted in the bottom of the airbox.
A Factory VT V8 Radiator and thermos will be installed.
The Standard Banana Manifold will be used.
Relays and fuses are to be mounted near the PCM

Really need to learn now what wires need to run into what relays and fuses for a "Stand Alone" Loom in order for the engine and trans to operate correctly.

Additionally, I would like to add an ALDL cable into the loom for tuning and diagnostics.

[Cleaver]

The relays I would like to use are GM part No: 92051068
These are the siemens / tyco narrow 5 pin relays - 12v 16A 5 Pin

So will I only need 5 relays?

Ignition
Starter
Fuel Pump
EFI (injectors)
Fans

[Dylan]

These are awesome mate. OEM look and high quality

https://www.swe-check.com.au/product/pr ... dmkit-564t

[Cleaver]

These are awesome mate. OEM look and high quality

https://www.swe-check.com.au/product/pr ... dmkit-564t

Thankyou mate for that, will be grabbing one of those plus relays after this post..

While I'm waiting for it all to arrive, do you think you could point me in the right direction with a VS3 or VT1 standalone loom pinout?

[brindo]

That relay block looks good.
Room is a bit tight on the rh side for the battery but it can be done, but not if your using the WB washer/overflow bottle. Charcoal canister will need a new home though.
Stretching my memory but I think its only the 5 relays, but add another for air conditioning if you are running it through the PCM. It can also a good idea to run your headlights through a relay, or at least the high beam anyway, so add another for that if your not already. And Holden ran the blower motor high speed for the heater/AC through a relay as well which was a worthy upgrade in the WB. So maybe think if you want to include them there as well or just keep it for the PCM.
Also maybe think about whether you want to include an immobiliser as can tie this in with the install as well.

On my WB that I converted, I used a VN loom so was a lot simpler. I used an aftermarket immobiliser with central locking included within the module. It worked well. But it was basically a matter of just following a factory wiring diagram and working out what went where. It was all fairly self explanatory and helps if you draw it out on some paper first.
ie there should be a fused wire supplying constant power to the PCM, another wire switched through a relay for the ignition etc You should be able to match up the loom colours to the wiring diagram and go from there.

Not entirely sure on the ALDL but from memory there is a white wire in the loom that goes across to the connector?
Hopefully someone else will chime in.