Hi, I have bought a cooler, which should be plugged into a 12V cigarette socket. However, when I tested the socket in the boot, it was powered even when the ignition was off. How is the easiest way to rewire it so that it turns off when the ignition is off?

I have some rough ideas, but would appreciate input on if any of them are impossible/hard to perform.

1. Swap the wire going to the socket by a nearby wire powered by ignition (are there any?)

2. Purchase (if it exists) or create a circuit that measures another line (e.g. light) and breaks the power to the socket when light turns off

3. Do a hack in the fuse box - run a cable from "the input" of a free ignition powered socket to "the output" of the boot socket

It's a fairly high current wire to the socket so be careful where you route it to. I would fit a relay into the circuit (contacts normally open for the socket feed wire) then trigger the relay from a switched ignition source. Relay only needs about 180 milliamps so any switched feed would be fine.

Or any easy way would be to just unplug it ?

I didnt even know there was a socket in the boot ?

Or any easy way would be to just unplug it ?

I didnt even know there was a socket in the boot ?

Not on the VRS, OP car is a Summer 2004

It's a fairly high current wire to the socket so be careful where you route it to. I would fit a relay into the circuit (contacts normally open for the socket feed wire) then trigger the relay from a switched ignition source. Relay only needs about 180 milliamps so any switched feed would be fine.

Yes a relay would probably work fine. Maybe I can use the rear lights as source, I suppose they are easily accessible. Do you know how to access the socket in the boot easiest?

Or any easy way would be to just unplug it ?

I didnt even know there was a socket in the boot ?

Of course, but during a long road trip, Murphy's law states that I will forget it the worst day possible, and end up with a flat battery. Some models have this socket yes.

Rear lights are not ignition switched.

Hi, I have bought a cooler, which should be plugged into a 12V cigarette socket. However, when I tested the socket in the boot, it was powered even when the ignition was off. How is the easiest way to rewire it so that it turns off when the ignition is off?

I have some rough ideas, but would appreciate input on if any of them are impossible/hard to perform.

1. Swap the wire going to the socket by a nearby wire powered by ignition (are there any?)

2. Purchase (if it exists) or create a circuit that measures another line (e.g. light) and breaks the power to the socket when light turns off

3. Do a hack in the fuse box - run a cable from "the input" of a free ignition powered socket to "the output" of the boot socket

Relay as suggested then use the switched live feed from the headunit.

Sent from my Desire HD using Tapatalk

Why not just put a flick switch beside the socket? Will take 10mins and no faffing around?

Why not just put a flick switch beside the socket? Will take 10mins and no faffing around?

Because one may put all that effort into installing it and still forget to actually switch it off

Just get one of these

http://cgi.ebay.co.uk/12V-Battery-Saver-Car-Van-/380332165731?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item588d904a63

No wiring changes. If battery drops below 11.6V it turns off the socket.

Koolatron do a better one if you can find one.

Rear lights are not ignition switched.

Well, mine are on as long as the ignition is on - isn't that good enough?

Relay as suggested then use the switched live feed from the headunit.

Sounds like a good idea, but then I would have to take wires from the radio to the back of the car.. It seems easier to use a wire accessible in the boot

Anyways, is it possible to buy a relay as a box with plugs so that I can easily fit everything and remove it later? (actually, I'm a engineer working with electronics, but I really want a simple solution that is easy to remove before selling the car )

Because one may put all that effort into installing it and still forget to actually switch it off

Precisely Unplugging is just as easy as using a switch.

Just get one of these

http://cgi.ebay.co.uk/12V-Battery-Saver-Car-Van-/380332165731?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item588d904a63

No wiring changes. If battery drops below 11.6V it turns off the socket.

Koolatron do a better one if you can find one.

Thanks, but I don't want to use the battery at all when I'm not driving... but this would be the second best solution

Well, mine are on as long as the ignition is on - isn't that good enough?

Sounds like a good idea, but then I would have to take wires from the radio to the back of the car.. It seems easier to use a wire accessible in the boot

Anyways, is it possible to buy a relay as a box with plugs so that I can easily fit everything and remove it later? (actually, I'm a engineer working with electronics, but I really want a simple solution that is easy to remove before selling the car )

Precisely Unplugging is just as easy as using a switch.

Thanks, but I don't want to use the battery at all when I'm not driving... but this would be the second best solution

Dont forget a relay takes current to pull the contacts together.It takes from about 150mA (0.15A) to 500mA(0.5A)

If left 'ON' where coil is being energised,it will deplete the battery,eventually.

The correct solution is to use a fused separate 15A rated cable from the fusebox area,switched off when ignition key is removed.

Edited 14 June, 201115 yr by AndyPandy

Well, mine are on as long as the ignition is on - isn't that good enough?

Sounds like a good idea, but then I would have to take wires from the radio to the back of the car.. It seems easier to use a wire accessible in the boot

Anyways, is it possible to buy a relay as a box with plugs so that I can easily fit everything and remove it later? (actually, I'm a engineer working with electronics, but I really want a simple solution that is easy to remove before selling the car )

Precisely Unplugging is just as easy as using a switch.

Thanks, but I don't want to use the battery at all when I'm not driving... but this would be the second best solution

Dont forget a relay takes current to pull the contacts together.It takes from about 150mA (0.15A) to 500mA(0.5A)

If left 'ON' where coil is being energised,it will deplete the battery,eventually.

Edited 14 June, 201115 yr by AndyPandy