Is there a wire at the rear 1/2 of a TF Executive wagon that is in constant power (active) as I have to tap into it
I have checked the trailer points but they are not constantly active
Any advice appreciated

hey what you need it for?

The only one I could think of would be the interior light perhaps, most cars have a constant power here as the door switch is a negative switch

Do not run too much juice through it though as it is not going to handle it, if you short this out you may burn as the length from the light to the fuse is a fair way.

hey madmagna what about the power cable going to his boot light because i know its constant... hang on he has a wagon, do they still have a "boot" light? and that would still be constant (i think?:nuts: )

That is the one I was talking about, the Wagon has a roof mounted light at the back

hey what you need it for?

To put a 12v power port in the rear cargo area and have it live so the ign does not need to be turned on

I will advise against this.

What you will do, depending on what you connect to the power port is:

At best: Blow fuses
At worst: melt part of your harness.

What you need to do is:

Find a constant +12V wire supply at the front of the car.

Tap into this (3mm wire).
Run this 3mm wire, to a relay*
Run a power wire from the fuse box, to the relay.
Run this wire to the back for your outlet.

Wiring a Bosch relay:
Pin 86: Earth
Pin 30: +12V feed from fuse box
Pin 85: +12V feed from constant +12V
Pin 87: +12V to outlet

Yeah I will do this as I have a few relays and an abundant of 3 - 4 mm wire It seems safer that just doing an inline 15A fuse by itself
Project for Sat morning
The only reason I was going to tap into a supply at the rear of the car was so I did not have to run a new wire the length of the car but it would seem the safer and best alternative to do it

Why the relay? I have been wiring constant power to outlets for years and never needed to use one. If you want constant power a relay is useless as you will need the ignition to activeate the relay either on acc or on ignition on thus defeates the purpose of a constant power supply.

If you are running anything heavy, you have 2 options, put a secondary fuse at the socket end as well to double protect or run a new cable from the front to the back.

Keep in mind that the cig lighter or the acc socket as it is called on many cars also runs a very thin wire these days, the good old third gen is a fine example

The only time you need a relay is when you intend to switch an item such as lights, horn etc, the relay takes the load off the switch not the circuit.

:stoopid:
I just ran a line from the battery, put a fuse in between when fitting a UHF radio on the weekend to my work van. Also ran a constant power lead from the radio, again fused it, to a power outlet for my engel fridge.

Why the relay?

Exactly what i was thinking.

There is absolutely no reason to have a relay in that circuit. it will not do anything.

Depending what you plan to plug in i'd say run 6mm. Then you'll be able to run a camping fridge should the need arise.

Just run it straight from the battery with a fuse in line and you'll be fine.

Mal,

Re-read my post - I said to trigger the relay with a constant +12V.

Depending on what you are planning to plug in, and what wires you use - I'de run a fuse and a simple on/off switch on the relay earth (mounted in the boot for easy access).

Re-read my post - I said to trigger the relay with a constant +12V.

That is pointless. How can you triger a constant with a constant. (I know how, the point is it gains nothing)


Depending on what you are planning to plug in, and what wires you use - I'de run a fuse and a simple on/off switch on the relay earth (mounted in the boot for easy access).

If your going to put a switch in the boot just put a swithc inline and the constant. (or the earth for that matter)

There is no need at all for a relay in the setup he's chasing.


You would only need a relay if he was running 3mm or 6mm (or anyother diameter) direct from the battery to handle a higher current that the factory wiring can handle, and want it to only switch on with acc or ign power. Then and only then would you need a realy.

Well I wired up a power plug in the rear cargo area
Tapped into the constant power in the rear interior light and fed the wire down the inside trim and put an inline 10A fuse on the wire
Have used it and it is all OK so far
Would it be worth while upgrading the fuse for interior illumination to the next size as well