Is it possible to splice in a wire somewhere and manually turn on the backup light on our cars?

I am working on a trailer backup system and want to use existing wiring to power it. I do not want this to run all the time (cameras WILL die if you do this) so I am thinking about using the existing wiring for backup light, which I want to trigger using a button.

Can this be done?

 

It sounds like we would be looking for something more specific here, like you want to power a backup camera on a whim. Is this the case?

I need to look into what year your vehicle is, because it makes a difference on the wiring diagram.

 

You could tap into the hot lead to the back-up lights to trigger a relay that powers up the other lights from a new direct source. That way you won't over load the existing circuit and the new lights will only be on when in reverse - if that is what you want.

 

That's the opposite of what I want - I apologize for not expressing myself clearly.
Let's put aside the whole camera setup. Here is a basic question:

If I wanted to turn on the existing , built in factory backup light, using a button - how would I go about it?

 

Exactly. Except I trying to use stock back-up light wiring.

 

Automatic or manual transmission? With or without trailer tow package relay block under the hood?

 

Automatic, tow package I THINK.

The reason I omitted these things is my double din radio seems to be aware when gear selector is in reverse so my plan was to tap in there.

 

I'm not sure if sending power into the circuit there is a good idea or not. It might backfeed the PCM. If the trailer relays are under the hood, there's one for trailer reverse lights that might work for what you're trying to do. I'll look at the wiring diagram and see if I can figure it out.

 

After looking at the wiring diagrams, I think you can simply supply +12v power to the black wire w/pink tracer coming from pin 11 on the DTR sensor. That should activate the reverse lights on the vehicle and activate the trailer reverse light relay, if it has one. The diagram shows that circuit coming from a fuse, going through the DTR sensor and directly to the reverse light wiring without interacting with the PCM. The wire that comes from the fuse to the DTR sensor carrying +12v is a light blue wire w/pink tracer and goes to pin 9. If you connect the switch between that one and the one on pin 11, you would maintain the fuse protection for the circuit.

 

We're getting closer to the goal here, and why I asked. Fat good it does to power the backup lights... to turn on the camera... when the head unit won't even display the camera unless you're in reverse.

I need to know which head unit you have, so we can come up with a comprehensive solution.