Engine bay switched 12v power

[Stl-986]

I dont see any issues with mounting the device in the trunk, it does make sense. Requiring power to come FROM the trunk though is what makes no sense to me. Other then it just taking some time it's really not a big deal. That is how the wiring got there to begin with. What is there already has a purpose and it is sized accordingly.

It really should take only a couple of hours to run a wire to the distribution panel up front and wire into the ignition circuit. You can put the relay in the trunk but you need to get power that really on it's own and not fused with something else.

Not to say this will happen with this specific device but imagine you tap into a circuit that is also used by something such as the DME. The device you add draws more then the connected fuse and the fuse blows. You have now also shut off the computer and the car because of it. This is why when adding aftermarket items it is always best to go straight off the 12v source, use a relay, it's own inline fuse and if necessary trigger with ignition.

Keep in mind that most circuits have a fuse that is 10% or to the nearest size up of the devices connected. For example if a radio uses 12amp a 15amp fuse will be sized as will the wiring for 15amp. If lights will use 25amps it will be sized for 30 amps, etc. Rule of thumb is to add 10% of the load and go to the next size up.