[connorg99]

I bought an AUTO VOX M1 backup camera for my 2015 335i. It's a "one wire easy install" where you tap the reverse light and then run the wire from the trunk to the monitor. Because my reverse light wire doesn't supply 12v, I had to use a 4 pin relay that I picked up at O'Reilly. I've attached photos to show my setup.

Pin #30: Constant 12v (Hooked it up straight to the battery)
Pin #85: Ground (Connected this to the black ground camera wire with another wire and ran it to a bolt in the battery compartment)
Pin #86: Switch (Connected this to the blue/black reverse light wire)
Pin #87: The device I want to power (Connected the red camera wire)

The first issue I ran into was with the 1st relay. When putting the car in reverse, the relay was making a very obnoxious noise, as if the switch wasn't functioning properly and the monitor had a flickering black screen. I exchanged the part for a new one, and the 2nd relay did the same thing. I then went to Autozone to look for a 3rd different brand relay and bought a Novita RL44. Working perfectly, this seemed to do the trick, but over the course of two days it began to rattle and not work more and more often, ultimately ending up like the other two. Is there anything I'm doing wrong? At this point I'm debating running constant power with a manual switch...
I also saw that AUTO VOX sells a separate product for the backup camera called an anti-interference cable for BMW, Audi, Benz, etc. but I don't see how that's in any way related to my issue with the relays.

[rje]

Correct me if I'm wrong but the way I understand your install is that you put the ground wire black from the camera and pin 85 wire and attached them both and wire them to one ground source which is the bolt on the brace for the battery.

I though the black camera wire for ground should be connected to the brown wire which is the ground wire for the tail lights. This wire is beside the black/blue wire which is the reverse light wire.

Pin 85 then which is the ground for the relay is connected to a screw connected to the car body just like what you did here. Let me know if that this works.

[b-merf30]

I added a backup camera from Bam auto safety that works off the factory screen in my vehicle, so it may be a little different. But when their tech support was helping my installer, they made it a point to tell him "DO NOT GET THE POWER FROM THE CAMERA". So, maybe that's your issue as well. Try getting the 12v constant from an ignition switch or cigarette lighter.

Best of luck