At some point maybe I can take a picture for you, but in all reality - you really do need to read the factory schematics. I could read these in elementary school. They are not difficult. You have a customized van that has been rewired. Us guys, we are just shooting in the dark. If you at least refer to the schematics, you can start at the base. Start with GM and what they gave you. If your van was not equipped from the factory with a camera, then you likely do not have the connector for it. I have never studied for a 2006 so I am at a loss. I can tell you off the top of my head the colour of the wires in that connector, but it's pointless. It's also not verified like the schematic will be. Click on the link in my signature and search for your year. At least search for the nearest year available as I am not sure that there actually will be detailed schematics for you. I tend to believe that your wiring will be the exact same as a 2010.

Thanks for all the answers.
I read through the linked topic and also the possibility to pick up the light green cable at the BCM. If I understand correctly, however, is switched when inserting the reverse gear to 0 volts and if in P or something else, in 12V.
I do not understand that, because it should indeed come from the fuse box underhood actually 12V PLUS, if the Reverse gear is engaged. Or?
I'll check with a measuring device at the BCM, if that's the case with me.
My radio needs 12v signal to put the input on the camera and my camera needs 12V to turn on.

I was grumpy earlier, my apologies.

I have to get to mine at some point as I am changing the radio. I will not tie in at the BCM, I will tie in under my seat. I assumed it was 12+ while in reverse, I still believe that it likely is, however.. GM could have done anything. It is their system. Perhaps 12+ is required to open a relay so the video feed/camera does not work? I'll look into that when the time comes. That's not going to be for months as I have court and other needs to attend to now. Just so you understand, at least in later models, the BCM controls everything. The Fusebox, is just that. A fuse box. Aside from a few heavier amp relays, it controls nothing. On my truck, there is not even a throttle cable. It is all electronic. I believe the transmission is the same way. The computer will tell you when the truck is in reverse, not a switch on the transmission. That's old school.

I know that a + cable goes from the fuse box underhood to the BCM.
When R is engaged, 12V + is on the line. Only the BCM seems to invert that. So there has to be a cable to the BCM that I can tap into.
I'll take a look at the pipes for the BCM, maybe I'll find a way there.

Many thanks for your help!

That's not the correct circuit. After all, the reverse lights come ON when you reverse, right? That means they are getting 12V.
Trace the reverse lamps circuit back to its source.

I know that this can not be the right circuit.
But this is how it is described in the link in Post #10. There it is said that when R is applied the voltage goes to 0 and in all other gears to 12v. That's exactly what I think is very unlikely. That's what I meant when I said I'm going to measure that at the BCM.
If that's true, I'll have to grab 12v elsewhere. If that is NOT true, the problem is solved, then I will take the 12v from the BCM light green Cable.

I am 100% not sure of what I am typing without studying a schematic, but understand that if your vehicle is new enough that there is no magic reverse wire heading into the BCM. The BCM will get it's information from the ECM or some other module on the transmission. This will not be anything that you can tap. This will be either a low speed or high speed data bus. A digital signal. A CANBUS type signal. The BCM (or maybe even the ECM) will read that signal. It will then open or close a related low amperage relay built onto the circuit board inside the BCM/ECM. From here, a low amperage output signal wire will carry either 12+ volts or 0 volts to a relay elsewhere, likely in the fusebox. From the fusebox, the heavier amperage wire will run all the way back to your tail lights. A separate fused line will run to your camera.

That is how it all works. I am not positive on your 2006 model, but I am sure it is no different. I personally would not tap anything at the BCM. For my last two android radios, they each included a small canbus box. These boxes read the low speed data bus and send out a signal through their own reverse wire to feed into the radio. Perhaps that is really what you need. You need to go buy an aftermarket chime module that is complete with these functions. They do make them, they are very common. You hook it up with your radio at the factory radio connector. Either to do that, or hack the reverse wire that feeds the rear back up lights and run it to your dash. Whatever comes out of the BCM is low amperage and only meant to drive a relay in a fusebox.

I'm done with this thread. There are schematics and sound advice listed. Either take it or leave it.

Not quite. The BCM module does have some low impedance circuits which source power directly to things like courtesy lights. The BCM probably has some onboard power FETs.
You are right about the reverse lights though. They are relay controlled.

On my 2013 the reverse lamps are connected to a fuse F27 in the fusebox under the driver seat. There's nothing complicated about it.

it's right on the drawing guys...
Connector C318 pin D3, light green is the correct positive reverse circuit. The C318 connector is behind the drivers kick panel usually tucked behind the connector that goes to the door harness..
there is no "relay" for reverse lights on an 06

Hello LCAC_Man,
someone told me that under no circumstances should I take a cable that leads to a control unit.
If I see that correctly, that's the cable leading to the BCM. And supposedly it should then come to problems, if you pick it up from there.
Can you exclude that?
Thanks for your Reply