Thread: Two way switch set up ?

Why not use the switch inside as the master power supply to the switch in the rear then depending on the two switches you could turn the light on from either end, you would have to remember to have the rear swith on to operate from inside and you can still turn if off from the rear.

Other option is to buy a suitable light and add a second globe each with their own power supply and separate switches or just have two rear lights

This is scary....I'm looking to have a similar setup.......

I'm looking to operate the work light from the drivers seat, probably running off the main battery for reversing etc but then also switched in the back of Grimmy to run off the aux battery for camping etc..

Thinking of running the main wiring from the main battery with a spliced power connection and switch off the aux battery sharing a common earth.

I have a reversing / work light stuck on the back of the rangie above the upper tailgate, and it has two on off switches and is also wired into the reversing lights.

I just have three relays, yes lots to go wrong but seems to work for me. Just have a fused 12v feed from the battery, which runs into three relays, of which one is under the dash with a switch to feed the light, and two relays are up the back with one driven by 12 volts from the reverse light, and the other just with a switch on the drivers side parcel shelf holder thing.

The switch in the back of the car is run from a voltage monitored feed, which cuts out at about 12.5v I think, so it should work with the ignition off, whereas from memory the relay up the front is just wired to the cig lighter so it will only run when the acc is at least on.

How ever, the lamp in each case is powered through the relays by a fused 12v feed from the battery, which is an extra one I put in for the purpose, its always live.

probably gonna get told my cars gonna burn down now

Originally Posted by VladTepes

I'm not going to post here http://www.aulro.com/afvb/communicat...g-circuit.html because he may be doing something different.

What I am looking to do is control a rear light on my ute canopy.

I want two switches - one in dash and one in teh canopy, by which i can control the light.

I've just done the same for my "expedition truck" (for want of a better word). I have rear lights and fans controlled both by a switch panel above the drivers seat, and a switch panel in the back.

I DON'T want a normal two way switch arrangeemn like in a house where the switches are sometims up and sometimes down depending on where tyhe light was last swicthed.

.... however, this is the method that I used. It's straightforward, just requires one additional wire to run between the switches as a live feed.

I therefore think momentary switches are the way to go ? (with an appropriate relay).

I would like the momentary switch(es) toilluminate when the rear light is on (eg when the circuit is powered).

What type of really do I need to use, and how would i need to be wired up ?

To do what you want, within the criteria that you are describing, then a latching relay is the easiest solution without getting into more complicated circuitry.

First, pop into Jaycar and buy a couple of these:
IP67 Rated Iluminated Pushbutton Switch Red - Jaycar Electronics

Nice, pretty metallic momentary pushbutton switches that illuminate in red, green or blue, depending on what you buy. The reason I recommend these ones is that the bulb has independent contacts, which don't need power going through the switch in order to illuminate.

While you are in Jaycar, pick up one of these:
12V DIL Latching Mini Relay - Jaycar Electronics

A latching relay that should be fine for running interior lights. If you plan on drawing more juice, then I'd be looking for something a bit more heavy duty.

Both switches get wired in the same. +12v in one side, the other side out to the coil on the relay. This will be the momentary pulse required to turn on and off the relay.

Getting the switches to light at the same time is the next step, and to do this you will need to take a feed back from the relay to each switch.

Give me a few minutes and I'll scan in a schematic - it's easier than trying to describe it.

Originally Posted by mike_ie

To do what you want, within the criteria that you are describing, then a latching relay is the easiest solution without getting into more complicated circuitry.

There are "Ratcheting" type latching relays available where this will work (I had a quick look for a "Ratcheting" type latching relay in the Farnell cattledog but didn't come up with anything), however the relay you suggested seems to be a "set/reset" type latching relay.
Which means you will need an "On" and a "Off" switch at each end, totaling 4 switches, or use the extra contacts on the relay to select which coil needs to be used I.e. (But be fast on the switch or the relay will oscillate)


Also if you want a larger load just use the baby relay to drive the coil on a larger relay.

what about 2 of these
12 Volt Illuminated Momentary Switch - Jaycar Electronics

It's a momentary illuminated DPDT (you only need SPDT but can't see any on that site) wired the same way you do with dual switches on house lights. Would only work if the illumination can be separately activated (ie run a wire back from the rear switch to the front that illuminates when rear light is on

The easiest solution that fits your requirements would be 2* SPDT LATCHING push button switches setup in the standard house hold two way switching arrangement.

It will look the exact same as a having two momentary push button switches and is dead set simple.

For the switches I am referring to see:
APEM|8636A|SWITCH, SPDT, LATCHING | Farnell Australia

Schematic attached, meticulously drawn in "HB Pencil" Schematic drawing software...