Its finally in etch prime! Woohoo

[damienengland]

So I've pulled out the old EFI wiring harness to test fit and sure enough, its gonna need some work. Looks like some hack jobs have happened along the way and for the life of me, i cant figure out why its got a weird speed sensor plug at the gearbox end. But more importantly, i'm totally lost about two of the plugs. Can any 304 EFI gurus identify these plugs and what they're for?

20180804_152803.jpg 20180804_152811.jpg

[axistr]

Its been a while since I wired up my 304 in the Torana, but from memory the transmission harness was a round plug. (VR Clubsport engine 4L60E) I had to modify mine due to going manual box. Is the auto your going to run a 4l60e ? and are you sure those plugs are for the auto.? I would check the wire trace colours to make sure before you start to change anything. What model Holden is the engine from.? I have a couple of wiring diagrams if you get stuck.

[damienengland]

Thanks axistr. Yeah I've got a 304 and 4L60E from a VR SII as the base and the wiring loom is the auto version, so the big round plug clicked into the gearbox nicely. The two plugs in the picture are part of a wiring branch that must be on the engine side of the firewall and searching everywhere today, I've still got squat! Wouldn't mind any wiring diagrams if they are available.

Cheers, Damo

[axistr]

What colours are the wires your concerned about.

[damienengland]

1st plug has;

Violet, Red, Pink/Blue, Red/Black, Green/White

2nd plug has;

Brown, Brown, Green, Green, Blue, Green/Black, Blue/White

[axistr]

Gday Damien,

In my book it lists as follows,

1st Plug.

Violet = ECU terminal C14 to Oxygen sensor.
Violet = There is also a violet power feed from fuel pump relay to electric fuel pump. Also linked to oil pressure switch.

Red = ECM terminal D7 main feed wire to injectors, ignition coil, oil pressure relay, ignition module. (This should be a larger red wire to handle higher amperage).
Red = ECM terminal B8 to A/T control circuit. ( this would be a small red wire).

Pink/blue (KL) I don't have this wire listed.

red/black = goes from terminal C11 at the computer (ECM), to diagnostic plug terminal 9 the linked to body control wiring BCM.
There is also a red/black running from battery to 25amp fuse to terminal D1 at the ECM, and linked
to the EFI relay.

Green/white = terminal A1 at ECU goes to fuel pump relay.
Green/white = There is also a Green/white running from terminal A11 at ECM to A/T control circuit.

2nd Plug,

Brown = ECM terminal D9 to manifold air temp sensor (MAT sensor). Is also linked to MAP sensor.
Brown = There is also a brown wire at ECM terminal B12 to climate control module. This wire is most likely a trigger to bump up the idle when the A/C cuts in.
Brown = There is also a brown wire from the ignition module to coil, also feeds tacko and tacko signal.

Green = There isn't a single green wire listed in my wiring diagram it may not be related to EFI wiring. or a secondary sub connection.
Light green = ECM terminal C10 to MAP sensor.

Blue = ECM terminal C5 to throttle position sensor.
Blue = There is also a blue wire from ECM terminal B1 to power/economy switch.


Can't find a green/black but there is a light green/black.
Light green/black = ECM terminal C8 to idle air control motor.

Blue/white = ECM terminal B5 to speed sensor.

DSC_0052_4[2654].JPG


If you expand the attached photo you should be able to read it to help identify some wires.
Hope this helps.

Lenny.

[damienengland]

Thanks Lenny. That was some great sleuthing on a Sunday, hope you have some beers going. I have used your drawing and a Snap On one i found on the net, along with some point to point testing and worked out the following;

6 pin Plug on engine bay side of loom with 5 x wires
Red/Black D1 Power 12V+ to EFI relay contact
Green/White A1 Fuel Pump Relay 12V+ to coil
Pink/Blue C1 EFI Relay 12V+ to coil
Red N/A Oil Pressure Switch (to injector voltage after EFI relay)
Violet N/A Oil Pressure Switch (to Fuel Pump Relay)

8 pin connector on engine bay side of loom with 7 x wires
Brown Still no idea?
Brown Still no idea?
Green Still no idea?
Green Still no idea?
Blue Still no idea?
Green/Black A5 A/C Relay (assuming 12V+ out?)
Blue/White A8 A/C Cooling Fan Relay (assuming 12V+ out?)


There is also another plug, which is on the inside of the car section of the loom (not far from the ECM plugs) with the following;
Brown/White A12 Brake Fail Lamp
Pink - C1 Ignition Power 12V+
Blue - B1 A/T Control
Violet/White C12 Speedometer
White/Black D6 Diagnostic Enable (to diagnostic connector)
Yellow/Black A10 Trip Computer
Red/Black C11 Diagnostic Data (to Diagnostic Plug)
Brown/White A7 Engine Check Lamp

I will get to the bottom of the 5 x still unknown wires, but considering the 3 x plugs above are the only ones that would connect to the Commodore, this must constitute almost every wire that needs to be considered when slotting this drive train into an old car.

[damienengland]

Looks like tab doesn't format too well in the forum. Pic below of what i meant.

VR Harness ECM pinout.JPG

[axistr]

Your probably aware of this, but I got a bit confused when I wired up my car the first time. or you can cause a short and damage the ECM. Unlike the truck computers that I am a bit more familiar with, the Delco computers when triggering an output relay (example the thermos fans relay), when checking the ECM output terminal it is earthed, even with or without the ECM powered up. When the computer triggers the output it flips to a power circuit. I installed a manual override switch inside the cabin which illuminates when the fans are on either auto or when the switch is in override mode. I can't hear when my fans are running with the windows up, so its nice to see when their on. After lots of thinking I used two relays. The fan relay was wired terminal 30 12v feed and 35 to the fans. The relay trigger coil terminals, one side to earth and the other to the ECM output fan control terminal. When it gets to the set cut in temp it flips to 12v positive output pulls in the relay coil. I used a second relay for the manual override circuit which triggers and sends a positive power supply to the first relay terminal 35. Doing it this way doesn't interfere with the ECM causing a short. I run a small wire from terminal 35 to the manual switch so it only illuminates when the fans have a power supply.

Hope it makes sense and I haven't confused you.

[damienengland]

Hey axistr

Understand you perfectly...and good advice. Essentially, make sure I understand the Delco computer signals well and be very careful when adding non Commodore bits to it, as the inputs/outputs may be exposed to destructive signals.

Nice work around for the override switch and indicator lamp.

Cheers, Damo