Thread: way to run the 4wd accessories without ignition on

Which vehicle?

I have a switch in my disco that does this for me. It a push button that drives a self latching relay DPDT relay that taps the accessory wire and is setup so that the earth for the solenoid is through the ignition circuit so that as soon as you turn the ignition on the relay drops out.

of the two switches in the relay switch one makes NC from the accessory wire on the main key switch to the accessory circuit NO makes from the aux battery to the accessory circuit.

on switch 2 the NO circuit makes from the aux battery to the positive side of the solenoid.

the push button switch is a momentary switch that makes direct from the aux battery to the positive side of the solenoid.

My defender had it and so does fozzy.

edit... very bad proof read.... I managed to kill half the post.. and sent it anyway...

Hi, IMO the best would be to splice into the feed of those units with a fused live from the second battery through a 5 pin relay's N/C contact and connect the relay's coil to an ignition live...then when you switch off the ignition the relay closes and connetcs them to the second battery and to be more complex you can run the original live through the relay's N/O contact to avoid any backfeed when ignition is off if you see what i mean

For your stereo, you are going to have to look at the wiring diagram for your stereo. Usually the stereo will have a 12V feed to run the power (this keeps all of your station settings) and then a separate ignition feed to start the stereo.

For your UHF, you could just run it off the house (2nd) battery, the down side to this is once your house battery is dead then you might have to wait a bit once the car start to get voltage to the radio. In mine (2012 110) it takes less than a 30s.

If your car is a newer version and the Ignition voltage (I haven't checked my rave drawings) is run from a computer, then sticking 12V on the back end of the output transistor will blow the transistor, usually it fails so the voltage stays on.

Cheers Glen

I thought about this a few years ago, ideally an auto sensing switch that detects where the live feed is and switches to it.
So once the acc. is off it automatically switches to the aux. battery power feed and vice versa.

Hi,
I run a vew accessories of the back of a Traxide SC80.

With the slide on camper on the back, things run off the camper battery.

Without the camper, things run till the starter battery gets down a bit.

Cheers

Thats great thanks guys, glad it can be done.

Its a defender.


cheers