Electronic fuel pump wiring

[s2k_adz]

Hey guys,

Just been wiring in an electric fuel pump to fuel the new Webers.

My question is that everyone seems to talk about connecting it to a green wire. The only colours I have on the loom in this area are green/yellow, blue, black and blue (yes two blues). Please see the photos.

I'm not sure which I'm supposed to connect to. I have a yellow and black going to the fuel tank pump.

 

[jonbills]

Not sure I'd worry about colour -assuming you've got your fuel tank sender wires sorted already, I'd just see which wire has 12v +ve with the key in the run and start positions.

 

[Wyn]

Can't see that you have but might be an idea to rubber mount that fuel pump on a couple of rubber cotton reels between the mount plate

 

[Albrecht]

My question is that everyone seems to talk about connecting it to a green wire. The only colours I have on the loom in this area are green/yellow, blue, black and blue (yes two blues).

The "green wire" connection is in the dash loom.

On first generation cars, there is a green wire in that dash loom which is normally disconnected and taped off, ready for a nascent electric pump feed. You have to un-tape it and join it to the adjacent bullet connector. That gives you your ignition switch-activated positive feed at the end of the loom spur which includes the fuel gauge wiring.

 

[s2k_adz]

Can't see that you have but might be an idea to rubber mount that fuel pump on a couple of rubber cotton reels between the mount plate

Cheers Wyn, yea the mount is rubber mounted to the chassis.

@Albrecht I see what you mean. So the green wire in early cars is dash side. Mine is a late UK 260Z, do you know if it's similar under the dash or am I good to go? I'll have a check when I'm back from a weekend away.

Thanks @jonbills I'll get the old multimeter out. If more than one of the four have it does it matter which I use? I know it's supposed to run through a relay etc

 

[jonbills]

Thanks @jonbills I'll get the old multimeter out. If more than one of the four have it does it matter which I use? I know it's supposed to run through a relay etc

It might matter I suppose. On my car and at least one other I've worked on, the voltage was too low back there to reliably run the pump, so I ran a new supply back there and added a relay and just used the original wires to activate the relay (and then it wouldn't matter which!)

 

[Paul_S]

I did something very similar. I also added an inertia switch so it would cut power to the pump in the event of a crash.

 

[Rob Gaskin]

I think improving the earthing at the back is well worth it too.