Switches, 2 feeds, one load?

[BundyRumandCoke]

Yes, perhaps this could be in the electrical section, but I thought I would ask here.

Having bought an LED light for the rear of the GU recently, I am now looking at wiring it up. I want to run it so that it comes on with my reverse lights, but also be able to run it as an independant light, for camping, working ect.

I thought the easiest way would be to run a 2 feed/1 load switch, if such a beast exists. Switch it one way, and normal power from the reverse light circuit gets fed into the light, switch it the other way, and an aux power feed from the battery feeds the light directly, without the standard reverse lights coming on as well.

The other option I have thought of is something like running through a relay, with a diode in the feed from the reverse lights, so the power does not back feed to the reverse lights.

So, anyone have any ideas?

And I way just down at the auto elecky, asking about the same thing- he wasnt very helpful, and they had some HUGE LED work lights, about 12 inches square, with god knows how many LEDs in it. The thing was about 5 inches thick with the massive heat sink ion the back. Truely awesome to look at, but I didnt ask the price. Not when their 8 inch ligfht bars, which they are selling as work lights, are over $900 each. Lots of money out in the lines this way.

[Tiny]

You could do it with 2 relays on one switch use and always on relay for the reverse function ie switch off allows feed from reverse switch on and it turns the always on relay to the off position and turn the normal relay on allowing a feed from the battery

[tehekho]

Diodes

[Red Dog 4x4]

I did the same on my reverse light ( work lights ) one relay wired so it can be turned on when ever its needed, then the OEM reverse wire to the triger on the relay (after the switch) so when I go in to reverse the switch on the dash lights up that all it will do.


Red Dog

[dillza_69]

Diodes

x2 you need 1 diode which will cost you 30c job done

[BundyRumandCoke]

And I am also not really wanting to drill a hole through the bodywork for the power wire to the light, so I am thinking of grounding it to one of the mounting points (the spare wheel carrier bolts) and drilling straight through the centre of one of those bolts (bottom, it should be in compression, not tension from the weight of the wheel) to feed the power wire from the light to the inside of the rear door. Being a LED light, the power wire is not a huge diameter, so should not loose too much strength from the bolt.

[tehekho]

Diodes

x2 you need 1 diode which will cost you 30c job done

Two diodes - one for each source.

[mickyd555]

instead of diodes just use one of these switches
http://db.hella.com.au/cgi-bin/catalogu ... lmaint=215" onclick="window.open(this.href);return false;

connect the LED light or relay (i would still use a relay) to the terminal 54, then reverse light wire to L and constant power to R. this way you can use the light as a work light with the car running in nuetral if needed or it can be switched off altogether so it does not come on when reverse gear is selected.

this uses the KISS theory which is also fail safe.

[TheOtherLeft]

instead of diodes just use one of these switches
http://db.hella.com.au/cgi-bin/catalogu ... lmaint=215" onclick="window.open(this.href);return false;

connect the LED light or relay (i would still use a relay) to the terminal 54, then reverse light wire to L and constant power to R. this way you can use the light as a work light with the car running in nuetral if needed or it can be switched off altogether so it does not come on when reverse gear is selected.

this uses the KISS theory which is also fail safe.

x 2

[Shadow]

x3 what mickyD said.

All you need is a SPDT (single pole double throw) switch. One with either a middle off position(as Mickyd suggested), or a normal SPDT switch which only has 2 states.

Middle you hook to the + of the new reverse light. Top hook to power from reverse lights, Bottom hook to +12volt constant(fused).

Then you have the light comming on with reverse lights if switch is in UP position. Light on permanenetly if swtch in the DOWN position. Or if you get a switch with a centre off, you can also have it OFF.

http://www.jaycar.com.au/productView.as ... ATID=978#1" onclick="window.open(this.href);return false;

C&K are a great quality switch and would handle the current of your reverse light with out a relay.

http://www.jaycar.com.au/productView.as ... ATID=978#1" onclick="window.open(this.href);return false;

cheaper version. Might handle the current of your LED light. Whats the power of the light?

[TheOtherLeft]

x3 what mickyD said.

All you need is a SPDT (single pole double throw) switch. One with either a middle off position(as Mickyd suggested), or a normal SPDT switch which only has 2 states.

Middle you hook to the + of the new reverse light. Top hook to power from reverse lights, Bottom hook to +12volt constant(fused).

Then you have the light comming on with reverse lights if switch is in UP position. Light on permanenetly if swtch in the DOWN position. Or if you get a switch with a centre off, you can also have it OFF.

http://www.jaycar.com.au/productView.as ... ATID=978#1" onclick="window.open(this.href);return false;

C&K are a great quality switch and would handle the current of your reverse light with out a relay.

http://www.jaycar.com.au/productView.as ... ATID=978#1" onclick="window.open(this.href);return false;

cheaper version. Might handle the current of your LED light. Whats the power of the light?

I have this setup but using a 3 position switch with 6.4mm wide tabs for quick connectors. Much easier then solder tabs.

[dillza_69]

Diodes

x2 you need 1 diode which will cost you 30c job done

Two diodes - one for each source.

Na mate just one. I would draw a diagram and post it up but i really cant be farked.

[BundyRumandCoke]

Light is a 15 watt- 5 x 3 watt LEDs. Specs say less than 1 amp current draw.

[-Scott-]

Light is a 15 watt- 5 x 3 watt LEDs. Specs say less than 1 amp current draw.

On what voltage? You can't get 15W out of a 12V source for less than 1 Amp.

[Skegbudley]

http://www.outerlimits4x4.com/viewtopic ... t#p1996309" onclick="window.open(this.href);return false;

[BundyRumandCoke]

Light is a 15 watt- 5 x 3 watt LEDs. Specs say less than 1 amp current draw.

On what voltage? You can't get 15W out of a 12V source for less than 1 Amp.

Your right, I misread the specs.

The line on the specs says- Multi volt, Current draw 1 amp@ 12V, 0.55amp @ 24V

[ledgend80]

i think we need to get a sticky on this with a wiring diagram as this seems to get asked every 2nd week

[BundyRumandCoke]

Finished the mount today. Drilled the spare wheel carrier bolt to take the feed wire. I think I will take the simple solution, feed from the reverse light circuit- with a diode in that line- and a seperate feed from battery via ordinary switch to light.

Thanks for all the input.

[BundyRumandCoke]

So, because I live in a small, 2 bit tinpot town, where our internet is delivered by 2 tin cans and a piece of string, and the local hardware shop closes at midday on Saturday and doesnt open again till 8.30am Monday, a visit to the local auto electrician gained a quizzical- Whats a diode?? response look on his face, and to get anything like a Jaycar agent means a 2 hr drive, each way, I have ended up with what I think will be a workable solution, if someone would care to check my guesswork.

Using a relay and an On/Off switch, I am going to
Feed a fused hot 12v wire from battery to terminal 30 on the relay
Feed a fused switched wire from battery to terminal 87 on the relay
Feed a trigger wire from the standard reverse light circuit to terminal 85 on the relay
Hook an earth to terminal 86 on the relay
Take a supply wire to the LED light from terminal 87a on the relay.

If I have got it correct,
the relay should close when the reverse lights come on, feeding power through the normal circuit to the LED light- and will backfeed as far as the dashboard switch.

Flicking the dashboard switch on will feed power to terminal 87a which bridges to terminal 87, then to the LED light. Because the relay is not closed, the standard reverse lights will not be on.

It should also not matter if, perchance, I have the LED light on via the switch, and I happen to put it into reverse, as the power will only backfeed into the standard reverse light circuit anyhow.

Next time I am heading to the coast, I might look at getting the appropriate diodes to put into the 2 hot feeds, just to be on the safe side.

[BundyRumandCoke]

So, because I live in a small, 2 bit tinpot town, where our internet is delivered by 2 tin cans and a piece of string, and the local hardware shop closes at midday on Saturday and doesnt open again till 8.30am Monday, a visit to the local auto electrician gained a quizzical- Whats a diode?? response look on his face, and to get anything like a Jaycar agent means a 2 hr drive, each way, I have ended up with what I think will be a workable solution, if someone would care to check my guesswork.

Using a relay and an On/Off switch, I am going to
Feed a fused hot 12v wire from battery to terminal 30 on the relay
Feed a fused switched wire from battery to terminal 87 on the relay
Feed a trigger wire from the standard reverse light circuit to terminal 85 on the relay
Hook an earth to terminal 86 on the relay
Take a supply wire to the LED light from terminal 87a on the relay.

If I have got it correct,
the relay should close when the reverse lights come on, feeding power through the normal circuit to the LED light- and will backfeed as far as the dashboard switch.

Flicking the dashboard switch on will feed power to terminal 87a which bridges to terminal 87, then to the LED light. Because the relay is not closed, the standard reverse lights will not be on.

It should also not matter if, perchance, I have the LED light on via the switch, and I happen to put it into reverse, as the power will only backfeed into the standard reverse light circuit anyhow.

Next time I am heading to the coast, I might look at getting the appropriate diodes to put into the 2 hot feeds, just to be on the safe side.

Except I have been sold what appears to be a switched relay. It seems that in an unpowered state, the relay is connected from 30 to 87a. If I trigger the relay, then 30 connects to 87.

So, 30 out to the light, 85 earth, 86 in from reverse light circuit, 87 + from battery, 87a power b attery through dash switch.

Is this correct?

[mickyd555]

can you not get a on/off/on switch? Its far simpler than what your trying to do and you wont have a problem if the diode shits itself because it wont be there.

[Big_DP]

I have drawn this using exactly the same parts I have used for my setup, led worklight, harness switch etc. so you can get a better idea. Have a look but I will explain underneath.




Ryto FYI

Wired exactly like this the following will occur:

ON-ON Switch:

1. Switch in up position - running through same circuit as stock reverse lights using their fuse. Not disatrous for led's as they draw SFA current. The 24 watt light shown (which I use) only draws 2 amps so no biggy there. Aftermarket work light will only turn on when the reverse lights are activated aka in reverse gear.

2. Switch in down position - running directly from battery. Running through fuse block as a precaution but needs a tiny fuse. Work light will remain activated until the switch is flicked back onto the reverse circuit. In this instance the reverse circuit acts as your off position but your light will always have somewhat of an 'active' circuit on it.


ON-OFF-ON Switch:

1. Switch in up position - running through same circuit as stock reverse lights using their fuse. Not disatrous for led's as they draw SFA current. The 24 watt light shown (which I use) only draws 2 amps so no biggy there. Aftermarket work light will only turn on when the reverse lights are activated aka in reverse gear.

2. Switch in middle position - no contact is being made inside the switch to complete the circuit so this will never turn on until switched up or down onto a circuit. True 'OFF' position.

3. Switch in down position - running directly from battery. Running through fuse block as a precaution but needs a tiny fuse. Work light will remain activated until the switch is flicked back onto the reverse circuit. In this instance the reverse circuit acts as your off position but your light will always have somewhat of an 'active' circuit on it.

[BundyRumandCoke]

Thanks guys, it seems there are as many ways to do this as flies on a cow. I just about have it all sorted out, with all the rear work, relay, ect finished, just have to mount the switch, with the appropriate terminals, then run the hot wire and fuse holder from the battery.

[crozza]

Go here for all 4x4 switches
http://www.customrockers.com.au" onclick="window.open(this.href);return false;