Lighted SPDT wiring

[RBRONKEMA GHTFD]

Hey guys, I am looking to see if anyone can shed some light on this. I am stumped. I am wiring aux reverse lights on a truck for a guy. Simple? Yes. However I wired everything with a SPDT switch. The owner wants the ability to turn the lights on when the truck is not in reverse, (loading salt and for whatever else.) and also have the aux reverse lights to come on when the truck goes in reverse. The off position will be off and only the factory reverse lights will only come on. Here is a diagram of what I am talking about. Now my actual question. I am using a lighted SPDT switch however it is back feeding so no matter what position (except off) they all come on. Does anyone know where I would need to add a diode so it doesn't back feed or another relay and how it would need to be done so I can use the lighted switch. I do not want to use a metal SPDT switch. Thanks guys.

 

[JazzDad]

Just install your switch before the factory backup switch. Use the center terminal as "in" and one of the outside ones as "out", continuing to the factory switch. Then run a wire from the other "out" of your switch to the backup lights. Put the relay in your box of cool stuff to use later.


This assumes your switch can handle the current of the lights.

 

[RBRONKEMA GHTFD]

So I would have to make the connection at the fuse for the back up lamps then? I already ran all the wiring and installed everything so I would rather if its easier just install a diode or another relay. This is the switch.


Contura Switch SPDT Black ON-OFF-ON - Blue Sea Systems

 

[JazzDad]

Contura Switch SPDT Black ON-OFF-ON - Blue Sea Systems

20 amps at 12 volts. Can I assume the vehicle is 12 volts?


What is the total current draw of the backup lamps?

 

[RBRONKEMA GHTFD]

20 amps at 12 volts. Can I assume the vehicle is 12 volts?

What is the total current draw of the backup lamps?

Yes its a 03 gmc duramax diesel. Factory back up lamp fuse is 10-15 amps I believe and the auxs lights are led. I forget the lumens.

 

[rad123]

The diagram on the left is the way I have my truck wired up. The left side does not need diodes and the right does. I have the switch on my dash. If you have any questions, PM me.

 

[sheazle]

Since you are using a spdt automotive relay anyway you can do this without diodes and with a spst switch.





This is how I have my reverse lights wired on my F150. With the switch open the stock wiring is lined up, with the switch closed the reverse lights are powered from the battery directly and the stock reverse light wire is removed from the circuit mechanically so it can't back feed. I didn't put fuses in the drawing but they are very important.