Too many ground connections?

I installed a backup camera in the license plate light of my car. The camera looks like this:



The camera has a built 2-smd LED light separately powered from the camera. I used a relay because the reverse trigger is 6.5 volts and the camera is 12 volts. My car's daylight driving lights turn on the license plate lights so the LED should be always on when the car is on to match the second license plate light that is always on when the car is on. The camera should only be on when the car is in reverse.

Here is the problem. The LED is not on all the time. The LED only turns on when the car is in reverse and the camera is on. So I know the LED works and the camera works. I would like the LED to be on all the time.   I think I messed up in connecting too may grounds. Maybe I should connect only the reverse switch ground to 85 and not connect the incoming 12v ground to 85? Maybe the incoming 12 ground will pick up the grounds from the camera and LED lights to complete the circuit? Thoughts? Thanks.

from your diagram, it seems you connected it all correct.

I don't have the make and model or diagram of the internals of this unit, but from what I can think, if the LEDs are coming on only when the camera is on, there might be an internal relay that turns on the LEDS only when the camera is on.

Also if I may ask this, and I know I have no right to ask it perhaps, why would you want the LEDs to be on all the time? they are designed to illuminate behind the vehicle to aid the camera vision, and if you have it ON all the time, won't the light hurt the eyes of drivers behind you while you are driving forward? The license plate illuminators usually have a cover to prevent the light going straight behind, and illuminate only the license plate area. Please don't take this the wrong way, but just my humble question.

Thanks for the reply. The led lights in the camera housing are to replace the license plate light that was removed to fit the camera housing, not to illuminate the camera. The led lights point down to illuminate the license plate. There are two license plate lights. The camera housing replaced one of the license plate lights. When the daylight driving light option is selected, various lights stay on when the car is on, such as the headlights, some side markers, the rear lights and for what ever reason, the license plate lights. Because the license plate lights are on during the day from the daylight driving light option, I used the 12 volt from the license plate lights to power both the camera (when triggered on by the relay) and the camera housing LED lights (total draw is less than the old license plate bulb that was removed). The issue is at night, only the left side license plate light is on. The right license plate light which is now the led in the camera housing is off unless I am in reverse. The car is a 2009 Porsche Cayenne that came with a factory backup camera, but I did not like the fixed angle of the factory camera, so I recently installed this camera which replaced one of the license plate lights.

The led lights in the camera housing have separate power wires from the camera so that the led can stay on independently of the camera. The camera only turns on when in reverse. The led lights can be wired (a) to stay on all the time or (b) to stay on all the time only at night or (c) to turn on only when the camera is on. Options (a) and (b) are the correct options. Option (c) is not desired as the led does not assist the camera.

ok that makes it very clear now, I understand this 2-set LED lights are replacing one of the factory license plate lights.       

Does this kit come with 4 wires (2 pairs)? Looks like it, from your diagram and notes.    Can you try connecting 12 volts (+ and -) just to the LEDs in this camera-kit, and see if both the License plate LEDS (factory/left and camera/right) come on (and off) simultaneously?    Like I said before, your diagram seems perfect.

Also where do the 2 wires to the reverse-switch go to?   Did you add a switch for turning on the camera?

I did this several years ago in one of my vehicles that had no camera. I just connected the reverse-lights power to the camera, so the camera would come on only when in reverse. Your camera comes on only in reverse, so you got that part right. For LEDs, check if they come on and off, independently of the camera.

The camera comes with two pairs of black/red, one pair for the led and one pair for the camera, and a yellow wire for the video. The two wires for the reverse switch come from the front of the car, presumably from a module that senses when the car is in reverse, which turns on the camera by way of the relay, and changes the monitor screen from the radio to display the backup video. The switch wires previously were connected to the factory backup camera, but I disconnected the factory backup camera and connected the switch wires to the relay, as the switch wires are 6.5 volts, and the new backup camera is 12 volts. Before the installation, I tested the led pair to the car's license plate light pair and the led worked. Sounds like am I am going to have to open up the trim and start rearranging wires to see if I can get the led to stay on.

The reason I am powering the camera/led with the license plate light wires is because the license plate light wires are hot during the day (from the daylight driving lights option) and at night from the regular lights. And I needed power to the camera relay day and night as I want the backup camera to work day and night. I could have used another "always on when the car is on" source to power the camera/led but the license plate light wires were there and easily accessible.

I see no reason for it not to work like you want it to, based on your circuit diagram.
The only points I can say are
1. you really don't need the incoming ground to connect to 85. Although it does no harm. (just an extra ground).
2. if the leds are coming on only when the camera is on, it is possible that the wire from the incoming ground to the led may not be connected (loose connection) and the led is getting its negative in series, from when the camera is powered, in essence putting the camera and leds in series.   Does the led (on the camera kit) seem a little dim? If yes, that could be the possible reason.   

Or perhaps you already removed the trim and figured out the wiring by now. If you are like me, you probably will not sleep until this is resolved.   Hope you don't have to pull to much plastic or wires, and get this done in the least amount of work and troubles.   Let me know how it goes.

I pulled the trim and cut the 12v ground wire going to 85. That had no impact. The camera still works, but the LED still only turns on when the camera is on. The LED appears bright when it is on. My next step is to pull the camera housing and check the wiring connections to the separate camera and LED pairs.

Subject to checking the separate camera and LED pairs, I am confused at this point because LEDs in general have directional current flow so if I simply mixed up the black and red LED pair, I am assuming the LED would not work at all, regardless if the camera was off or on. When the camera is off, the camera receives no power because of the relay and I separately tested the LED pair before installation so I know the LED works without camera power. I could have mistakenly wired the LED in series with the camera but that would mean I really messed up what I thought I was wiring and soldered the black camera ground wire to the red LED 12v wire, and then the black LED ground wire to the black 12v ground wire. Oh well, I will find out when I pull the camera housing in the next few days.

Another thought. Assuming I pull the camera housing and the connections are all correct, I have a thought. I need a diode on the camera ground wire to prevent the LED ground from flowing back into the camera and possibly creating an open loop. Maybe that is what is preventing the LED from turning on absent the camera being on. When the camera turns on, both the LED and the Camera loop close and both turn on. When the camera is off, the LED loop is acting as if it is open, possibly because the LED return/ground current is flowing into the camera instead of into the 12v ground wire. If that is the case, it has not fried the camera as the camera still works. Just need to figure out which diode to buy if the wiring all checks out.

CASE CLOSED! I figured out the issue. The splice at B or the 12 volt wire coming off the splice at B to the LED is faulty. I first cut the ground at location A with no effect. At the relay, I was left with the reverse camera turn on switch 6.5 volts going into 86 and returning ground on 85 using the ground wire associated with the 6.5 volt switch wire. Camera 12 volt power was going into the relay at 30, and when the relay was triggered, 87 would power the camera with 12 volts. The camera ground completes the loop by connecting to the ground wire associated with the 12 volt wire connected to 30.

I next pulled the camera housing. I cut the ground from the camera to see if it was a power feedback issue, which it was not as the LED still did not turn on. The camera would not turn on either as the ground was cut telling me that I had a good ground going to both the camera and the LED. I then cut the pair connected to the LED and there was no voltage, revealing that the 12 volt wire going into the LED was faulty. I am guessing the splice at location B is faulty, or the 12v wire connecting location B to the LED 12v wire is faulty. The splice at location B is behind the rear hatch trim which is a lengthy process to remove and I wanted to avoid that again.

I was able to fish a red/black pair to the driver side license plate light and I tapped into that 12v and ground to power the LED in the passenger side camera housing. I reconnected the camera ground where I had cut it for testing purposes. I turned on the car and the camera housing LED was on independent of the camera being on. That was good. But the driver side license plate was no longer on. Woops, I put the driver side LED bulb into its socket backwards. LED has directional current. I reversed the bulb in the driver side license plate light and everything worked. Below is a clean wire diagram. Thanks for your help. On to the next project.
     

Bottom diagram correct BUT feed the camera from the rev light bulb feed, surely that's 12V+ thus eliminating the relay.
That's how I always do it.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Your suggestions make sense for 99.99% of backup installations, but on my car (2009 Cayenne), for reasons I am not sure why but the manufacture intended, the backup video is displayed for up to 30 seconds after the car is taken out of reverse, or less if the car gets over a certain forward speed (6 MPH), the parking brake is applied or a different input is manually selected on the display, such as the radio. If after the 30 seconds the reverse display is still showing, the display automatically returns to the last display before the car was put into reverse. If I powered the camera with the reverse bulb, the video screen would be blank for those 30 seconds. I needed the relay because the wire that tells the camera to turn on and off is only 6.5 volts, whereas the camera is rated 12 volts. I probably should have tested the camera to see if it would work on 6.5 volts but I forgot to do that. If the camera would work on 6.5 volts, I could have wired the camera directly to the 6.5 volt camera on/off wires and skipped the relay. On another note, here is a screen shot of the backup camera in action. Thanks.

    

OK, maybe I missed that earlier.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Hi,...i am a new user here. As per my knowledge they are designed to illuminate behind the vehicle to aid the camera vision, and if you have it ON all the time, won't the light hurt the eyes of drivers behind you while you are driving forward? The license plate illuminators usually have a cover to prevent the light going straight behind, and illuminate only the license plate area.

The license plate light points down and illuminates the license plate only. It does not shine backwards nor assist the rear view camera. Other backup cameras may have assist lights that point backwards and illuminate when the backup camera is on, but not this one. Thanks.