2014 CX-5 3rd party head unit not automatically switching to reverse cam

Hey there. I recently bought a Pioneer DMH-Z6350BT to install in my 2014 Mazda CX-5.

I've got it hooked up and working with one exception – the unit doesn't automatically switch to the backup cam when I put the car in reverse (my car's an auto). Audio, radio, carplay, steering wheel controls, etc. all working correctly.

I've kept the factory camera and used an AX-MAZCAM-6V to wire it to the head unit.

I can manually activate the "Camera view" on the head unit and it works as expected, so the camera's getting power correctly and I believe that means I've identified the right reverse wire (and hooked it to the purple/white reverse wire of the head unit). When the car's in reverse, the camera view on the unit shows the backup camera footage including the guidance lines. When the car's in any other gear, it's just a black screen.

I've got the backup cam set to "On" in the unit's settings, and set the polarity to "Battery" (although I've also tried changing that to "Ground" and it doesn't make a difference).

Is it possible that the MAZCAM stepping down the voltage is interfering with the head unit detecting the gear change?

Is there anything else I can try to get this working?
 
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Measure the voltage on the reverse wire on the car's radio harness when in reverse. The deck is looking for 12V, if it doesn't get that 12V, it won't switch.
 
Gotcha - this seems to be the problem, thanks.

I've unhooked the MAZCAM from the head unit reverse wire, and now the head unit switches to reverse correctly.

But obviously there's just a black screen on the camera view now, because the camera is 6V and won't work without the converter.

Is there somewhere else I can connect the MAZCAM wire that will let me keep 12V going to the head unit but still power the camera?
 
Keep the MAZCAM 6V converter, you need that. If you feed the factory camera 12V, you'll smoke it.

To get your deck to switch, you'll need to find the wire in the shifter harness that engages the backup lights, as those do run on regular 12V.

Now, just wire those reverse lights to the deck, and you're in business.
 
@bonk_ some questions regarding your setup:
- do you have a central command knob, next to the shifter?
- if so, can you still use it with the aftermarket unit?
- have you lost any functionality - steering wheel controls etc.? If not, did you get any additional gear for it?
 
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@bonk_ some questions regarding your setup:
- do you have a central command knob, next to the shifter?
- if so, can you still use it with the aftermarket unit?
- have you lost any functionality - steering wheel controls etc.? If not, did you get any additional gear for it?
No, no central knob (other than the driver 😅). This is a 2014 CX-5.

I didn't lose any functionality (other than automatic rear camera detection), but I did buy a steering wheel control adapter specifically for this car. It's this one from Aerpro: Aerpro | First Choice
 
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