Fuel pump wiring

[Sx279]

Hi there I'm starting a track car project e30
Ive completely removed the in car loom (pulled though the bolk head at the moment)
I need to keep the car mobile for a while longer so I was going to run a switched live feed to the pump till I make my own in car loom but there's 8 wires going to the fuel pump plug ( on the back seat)

What wire is the live to the pump and what one is the earth?
Chears

[daimlerman]

BMW use plain brown for earth. A brown cable with a tracer colour is a wire heading for earth via something like a sensor or light.

Feed to the fuel pump is green/violet.

In general;
Red is constant live
Green is ign switched live

There are other basics,but I'm still learning as well!

[Sx279]

So basicly
Battery > fuse > switch > green&violet feed > pump > brown/earth

Thanks I'm going to make a loom for fuel
IE
Ignition live to relay then battery voltage to pump

Also is the pump relay switched by the ecu? and by earth or live if so?

Thanks..

[daimlerman]

The crank position sensor tells the ECU that the engine is turning,so the ECU lets the fuel pump switch on,via it's relay(usually the middle one of three,but can be identified by the green/violent attached to it's bum)BMW's idea is that the fuel pump is switched off when the engine stops,handy if the car is upside down and the ign still switched on and a fuel line is split!

[Sx279]

So I can bypass that with my temporary set up and the set up I intend to use?

[magpie]

some of the wires are for the fuel gauge.

find the cranked live from the blue relay [fuel pump] under the bonnet and run a live from there with an in-line fuse straight to the pump then earth the other pump pin where you like ,no need for a separate switch if you go this way .

[Sx279]

Basicly I'm in a bit of a predicament my e30 is parked out side my garage (work).
the whole interior loom is sitting on top of the engine at the moment due to welding but most of it ain't going back in IE all accessories.
but I need to keep it mobile in case I have to move it out the way for my boss

So if I just cut every thing out I no ain't going back in and keep everything that's connected to the ingntion switch connected it should all still run i hav been drawing up all my wiring diagrams for fuel, lights, starting,
Which I will be installing once all the welding has been done

[magpie]

if you only need the fuel pump to run then just give it 12v direct ?

[Grrrmachine]

i hav been drawing up all my wiring diagrams for fuel, lights, starting,
Which I will be installing once all the welding has been done

A lot of it's already done for you:

http://www.e30zone.net/e30zonewiki/inde ... g_Diagrams