Cooper mk1 fuel switch

[Charlynsane]

Hello Guys

I will put a switch on my Cooper mk1 to disconnect the fuel pump if there is any overflow with car

Can any one help me with wiring? I'm really dummy with electricity

Thank you

Charles

[timmy201]

The fuel pump wire is white and is fed power from the fuse block (although not fused)

You could wire your switch (and add a fuse) inline with the white wire from there to the fuel pump

[Charlynsane]

Thank you very much Timmy

Does this wire feed something else? can I grab it inside the car? maybe under the dash?

[mk1]

The fuel pump wire, is as has already been said, a white wire that connects to terminal number 3 on the fuse box. You can determine exactly which wire it is by turning on the ignition and listening to the fuel pump clicking. Remover each of the 3 white wires in turn. When you remove the corect wire the fuel pump will stop clicking.

Once you have determined the correct wire, turn off the ignition & DISCONNECT THE BATTERY!

Take a length of (preferably white) wire & put a spade connector on one end. connect this to the terminal in the fuse box. Run this wire to the dash, where you would like to position the switch. fit the switch & connect the wire to one side of it. Take another similar length of wire connect one end to the switch & run this wire back towards the fuse box. Connect the final end to the original fuel pump wire by means of a male spade terminal or by cutting & re soldering the wire, remembering to insulate the splice properly with either PVC tape of heat shrink sleeving, reconnect the battery & you are done.

Hope this makes sense.

[jayare]

You could also connect the switch where the front and rear wiring looms connect together near the wiper motor - you would need the bullet connectors here rather than spades. Assuming the car is LHD this may be more convenient for you,

JR

[Gray]

Or you can connect into it at the 5 way bullet connector where the front and rear looms join as I guess your car to be a left hand drive it would only be a short run through to the dash using just bullet connectors so easy to remove if you want.

[Gray]

Beat me to it JR!

[Charlynsane]

Hello Guys, thank your for your help

I'm going to wire under the dash to avoid to put a second "harness" in the engine bay

Can someone show me where is the 5 ways bullet connector that I need to modify? is it the one that is under the steering column?

[mk1]

The connections you need are tucked away behind the windscreen wiper motor, it is the connection between the front & rear halves of the wiring loom. This is why I suggested taking the feed off the fuse box, because it is straight forward & easy to complete.

[111Robin]

Why not just switch the ignition off ?. Why would you need to shut off the pump without turning off the ignition if the carbs are flooding?. I can see the benefit of an external cut off switch on a race car but not a road car. Is it an anti theft thing ?. I can understand that being useful but not for stopping flooding while the engine is running.

[Charlynsane]

Is it possible to Get it under the dash board as well?

This white wire only feeds the pump?

I would like to get it just in case of overflood on the track, with a stuck float needle, I just cut the pump feed the time top empty my carbs and I switch it on again

[AndyPen]

The rear loom wires come down the passenger pillar and out through a grommet before popping through another in the metal by the wiper motor. Whilst it would be possible to cut into it there I personally wouldn't bother. The fuse box as Mark suggests is where I'd go, the wire can be hidden easily and fed back into the front bulkhead to a convenient spot inside.

We used to have fun hiding all this stuff thinking what great anti theft folks we were - ha ha.

[Fanfaniracing]

Running an engine on a Track and cutting the fuel pump seems a very bad if not dumb idea.

No or the bad fuel pressure can cause serious engine damage...

[850man]

Why not just switch the ignition off ?. Why would you need to shut off the pump without turning off the ignition if the carbs are flooding?. I can see the benefit of an external cut off switch on a race car but not a road car. Is it an anti theft thing ?. I can understand that being useful but not for stopping flooding while the engine is running.

I agree, just turn the key off. And then fix the reason why the carburettors are flooding.

[111Robin]

Why not just switch the ignition off ?. Why would you need to shut off the pump without turning off the ignition if the carbs are flooding?. I can see the benefit of an external cut off switch on a race car but not a road car. Is it an anti theft thing ?. I can understand that being useful but not for stopping flooding while the engine is running.

I agree, just turn the key off. And then fix the reason why the carburettors are flooding.

Carrying on driving knowing you have fuel pissing out of the carbs seems an unwise move, even if you switch off the pump. Is this a recognised modification used on the race scene ?.

[Charlynsane]

Why not just switch the ignition off ?. Why would you need to shut off the pump without turning off the ignition if the carbs are flooding?. I can see the benefit of an external cut off switch on a race car but not a road car. Is it an anti theft thing ?. I can understand that being useful but not for stopping flooding while the engine is running.

I agree, just turn the key off. And then fix the reason why the carburettors are flooding.

It was just a security switch, just the time to get my car on the side of the road.

Otherwise the car has brand new carbs.. I don't understand why the LH carb sometimes overflow, everything is ok,

any idea of what could be wrong?

I just had a look on superflow to upgrade the standard ones

[111Robin]

Why not just switch the ignition off ?. Why would you need to shut off the pump without turning off the ignition if the carbs are flooding?. I can see the benefit of an external cut off switch on a race car but not a road car. Is it an anti theft thing ?. I can understand that being useful but not for stopping flooding while the engine is running.

I agree, just turn the key off. And then fix the reason why the carburettors are flooding.

It was just a security switch, just the time to get my car on the side of the road.

Otherwise the car has brand new carbs.. I don't understand why the LH carb sometimes overflow, everything is ok,

any idea of what could be wrong?

I just had a look on superflow to upgrade the standard ones

That makes more sense, I thought you intended to carry on driving while switching the pump on and off. Do you have a filter in the fuel line ?. I can only suggest it is dirt from the tank however if it is all new (tank, lines, hoses) then it could just be a bad needle valve. Dirt would affect both carbs so if it is always the same side, try swapping the needle valves around to see if you transfer the fault to the other side, then you will know for sure. Could also be the float height is not correct so it's worth checking that as well.

[Charlynsane]

Hello Guys

Carbs are brand new, and I'm running fuel trough a Sytec race fuel filter

Il will change the needle,

any thoughts about super flow needles?

[mini129]

If you have air filters and you turn the fuel off whilst there is still spark you are likely to blow them through the bonnet. Then you will need a fire extinguisher
This is a problem experienced with incorrectly installed/ specified rev limiters and battery isolation switches.
The safest way that is easy to hide is a telemetric switch.
A frequency switch. It synchronises the explosion with the fuel delivery.

[mini129]

5AA95337-60D2-42A0-88AF-672E4F4D56C1.jpeg