multiple switches problem

Hey guys,

been awhile since I was on the forum, but I've hit a mental block on this one. Here's my problem. I have 3 outputs I'd like to control now: Front LED Bar, Roof LED Bar, Bed Lights, and Fog Lights. I have a switch with each one, running to the trigger wire on it's respective relay. Now, I want to have another switch that will activate all 4 outputs at once, specifically so when I get up in the woods I can throw all my lights on to light up the area around my cabin.

How the hell can I do this without creating backfeeds? My main concern is that if I wire it to do this, what's to stop all the outputs coming on when I just turn one switch on? I can't "see" a way to wire it to achieve what I want, but I know it's possible. I have a rough sketch done up to show you what I'm talking about.



Thanks in advance!

The first problem is that, at least by my math, Front LED Bar, Roof LED Bar, Bed Lights, and Fog Lights are actually 4 outputs, not 3.

There are two ways that come to mind to me to do this. The first would be to use all low current switches and diode isolate them. A diode resists the flow of current so it can be used to isolate the master switch from the individual switches.

The other way to do it is to use all 5 wire relays. Connect each individual light to pin 30 of the relay and connect the individual power source to 87. You could then tie Pin 87A of all relays together and run them through a high current switch or through another relay. If you go this route you need to make sure you use a relay or switch big enough for all the current you need to pull.

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Kevin Pierson

Would something as simple as this work?



The switches I'm using are 20A @ 12V. This really isn't that complicated, I know, I have no idea why I'm hitting a wall on it! haha

That should work, use adequately sized diodes and ensure you calculate the total load being applied to the switch, so that does not exceed the capacity of your switch.

I'm assuming a 1A diodes should do, as these shouldn't have a load on them as such other than the small light in the switch (100ma maybe?), they'll just be ran to the relay to activate the coil, and the relays power source will run the lights.

What do you think?

You are correct, from the diagram i thought you were applying voltage directly to the lights.

Excellent! Thanks a lot! I'll get those diodes picked up today!