Adding extra reverse lights wiring question

Aloha all,
Had a question that im hoping someone with more electrical savvy than I can help me figure out.

Cut and dry version: Can i control 1 relay with 2 switches and not feedback to the power source?

Long version: Iʻm adding 2 extra LED reverse lights that I want to turn on when i shit into reverse and bought a pre-made wiring harness from Amazon to try to help save some time. The harness came with a switch to turn the lights on and off which is also lit when turned on. The harness was wired to mount the relay under the hood, but because i didnt want to run so many wires back to the rear of my truck, I cut the wire and mounted the relay in the rear by my tail lights and ran a wire from the relay to the battery where i reconnected the fuse. I then connected the rest of the wiring as instructed. I found the red/black wire that powered my reverse lights and spliced in the trigger wire to the relay, this wire is also connected to the switch. I tried putting the truck in reverse with key on and it works as i imagined. However, when I plug in the switch and try to use the switch to turn on the lights without being in reverse, it lights up the reverse lights too and i hear a click in my dash. If youʻre reading this and you understand whats going on, please help me out.

 

I am on my iPad in bed, but posting here so I can find this again in the morning. What you want to do is pretty easy, and if no one else answers tonight, I’ll reply to you tomorrow.

 

LED`s draw so little current just connect to the back up lights at the rear of the truck.

Making a Good clean Water proof splice ( solder and Heat Shrink) just run the ground to a good ground on the frame

LED`s make sure the Polarity is correct before making permanent connections.

Unless you want to add all those extra unneeded parts .

 

You’d need to diode that “bridge” if you want it to work how with both the other reverse lights and the switch independently.

when you connect the switch, power is going across your bridge to the factory reverse light. Should be very easy to add a diode in there.

Are you trying to be able to switch on the aux lights without the trans being in reverse?

 

I guess I did not take notice you wanted to control the extra lights without the truck in reverse .

I really never gave that a thought because my lights are only for backing up in the dark.

 

Tailgaters?

 

Rock lights?

 

Camping?
Loading/unloading stuff in the dark?

 

Myself I have no need for other then more lights backing up in the dark.

Camping is not every talked about when you grew up with no indoor plumbing or central heat .

Fork lifts tend to have lights

 

you're over thinking this.

You simply need a Single Pole Double Throw (SPDT) switch and a relay like you have sketched out.
A SPDT switch can take a signal (12v+ in this case) from either the tail light circuit, or directly from the battery (or any other circuit really). These are sometimes called 3 position switches or ON-OFF-ON or ON-OFF-AUTO.
The SPDT switch will isolate your tail light circuit from your extra 12v circuit you are adding.

 

Okay? This person might have desires you do not.

 

Yes

Yes

Yes

Yes, we'll... maybe...

Yes to all of those reasons mentioned as well as some others. Here in Hawai'i, we have some serious biter cops who don't like modded vehicles , so I'd like to be able to say "they're just for looks" if I have to. Also, sometimes when I'm skinning a pig or cleaning fish, it's nice to be able to have the option of not being in reverse and having them. As another option, every once in a while when I get a call to tow someone out of the mud, they might be nice to have when hooking them up. Just to add one more, my neighbors bedroom window is in direct line with my driveway, so if I leave at night, I don't feel stoked about lighting his room up as I leave. Maybe now we can get back to answering the question lol

I like the idea of the SPDT

 

This would replace the bridge I take it?
Sorry. I know there's a simple solution to the wiring, I've just had lots of bad teachers and am still fixing unsound theories in my ideas. Much appreciation for all your folks' help and cents

 

I am Sorry I tried to help my mistake!

 

Did you?

 

No worries brah. Im thinking about putting lights on my forklift, thanks to your post

 

Not exactly.

The switch will have 3 contacts, 2 are inputs, one is output. There is no ground unless the switch has a built in light.

Your output goes to the relay to trigger power from the battery to go to your aux reverse lights.

One input comes from the 12v supply to the reverse light circuit (stock tail lights). I believe this is the R-B wire you found.

The other input comes from any 12v supply. This will be used to trigger the relay for your aux lights whenever you want. This could be directly from the battery, but it could also just be from the gauge circuit or another circuit that is used to power stock switches. If you go to the battery you can do it with the truck off. If you go to a truck circuit then you can only do it when the key is in the ignition.

Most of the time you will just leave the switch in the “auto” position, or the position using the stock tail light circuit to trigger your aux lights. You can always flip the switch to the other side to turn them on whenever you want. Or you can just turn it off in the middle (usually). This is how I have mine wired and it was worked perfectly since day one.

Make sense?

 

This is indeed a great explanation…thanks!

 

Gotcha! Yup, makes perfect sense. Just needed to flip my thinking 180⁰ and look at it from the power supply side instead of the ground. Thanks!
I'll try to post what I do and maybe someone else will find it helpful... still need to do the introduction thing and post what I've done to this taco since I got it last October. More to come

 

You sure you want them to come on automatically with the reverse lights? I did the same thing but went against that for times I'm backing out of parking spaces so I don't blind everyone.

I bought 2 4" led pods on eBay for $14, a wiring harness for $15 that included am illuminated switch. I extended the wiring harness and put loom over the entire thing and put weatherpack connectors on the LED pods in case I need to disconnect or replace them.
Super simple. Took a few hours with the main time consumption being routing the wiring. And there have been alot of times where hitting the light switch while the truck was in park is helpful for loading stuff in the bed or doing stuff around the farm. Just my 2 cents.