Im a complete numpty

[BaroqueMoon]

I hope someone can help.
I replaced the rear plinth on my 75 saloon and disconnected the wired rear view camera during the process.
I wanted to replace it with a night vision camera. Well...I did just that. I used common sense and cut and spliced a bit and simply replaced the old camera with new.
Put it into reverse. IT WORKS.
Now for the numpty part.
The power cable on the camera had a core and outer wiring. The power cable I was connecting to had just a wire, no shielding (or whatever it is).
I connected core to core and all went fine. Then for some completely unknown reason I twisted the outer layer wire into the join.
Put the car into reverse. Black screen.
Ok so I shouldn't have done that. No problem just hook it up like it was before.
Put the car into reverse. Nothing. No image, no blue screen with BACK on it. Simply no response when engaging reverse.
Maybe I should reset the DD unit (Chinese type like Radio-Guy sells).
Still nothing when engaging reverse. All else working fine.
What has this numpty done and can it be undone?
I clearly have no clue about electrics so be gentle

Matt

[KarlF]

Sounds like you've popped a fuse somewhere. Might be worth posting the model of stereo you have.

[Steve916]

As above, do you have an inline fuse supplying the camera? It sounds like this has popped, therefore if the camera isn't powering up, you won't get voltage on the 'back' wire of the dd.

[BaroqueMoon]

Originally Posted by Steve916

As above, do you have an inline fuse supplying the camera? It sounds like this has popped, therefore if the camera isn't powering up, you won't get voltage on the 'back' wire of the dd.

I put the original camera back and still no difference
All is working on the unit. It just no longer does anything when I engage reverse. When there was no camera attached I would get a blue screen when in reverse. Now it doesn't take any notice.
Ill find out if the reverse switch has its own fuse. Is that likely?

[BaroqueMoon]

Just read that there's a fuse for reversing lights and cruise controll. I'll be driving to an appointment later and if cruise isn't working I may have found the problem. Heck, I hope it's that simple

[BaroqueMoon]

Nope. Of course its not that simple.
The cruise control works but the reversing lights don't. They are both on the same fuse. I'm at a loss.
I guess its problem solving things like this that will educate me, assuming I work it out that is (sigh).

[BaroqueMoon]

Not only does the head unit ignore being in reverse it now seems the reversing lights don't work any longer too.
The fact that the parking aid still works should mean that the reverse switch on the auto box is still working yes?

[David Lawrence]

Originally Posted by BaroqueMoon

I hope someone can help.
I replaced the rear plinth on my 75 saloon and disconnected the wired rear view camera during the process.
I wanted to replace it with a night vision camera. Well...I did just that. I used common sense and cut and spliced a bit and simply replaced the old camera with new.
Put it into reverse. IT WORKS.
Now for the numpty part.
The power cable on the camera had a core and outer wiring. The power cable I was connecting to had just a wire, no shielding (or whatever it is).
I connected core to core and all went fine. Then for some completely unknown reason I twisted the outer layer wire into the join.
Put the car into reverse. Black screen.
Ok so I shouldn't have done that. No problem just hook it up like it was before.
Put the car into reverse. Nothing. No image, no blue screen with BACK on it. Simply no response when engaging reverse.
Maybe I should reset the DD unit (Chinese type like Radio-Guy sells).
Still nothing when engaging reverse. All else working fine.
What has this numpty done and can it be undone?
I clearly have no clue about electrics so be gentle

Matt

You shorted 12v to ground and the fuse didn't blow but something between the camera wires and the supply did. In my experience those camera power wires are very thin, one may have fused inside its insulation.

The reversing light switch on an auto is turning on a relay in the passenger fusebox (R4). Is that clicking? You might want to pull that relay out and test it in case you've fused its contacts. The good news is that if you have no volts on your camera or your lights, that relay pretty much protects everything else in the car from your short circuit.

To test the DD is still ok, just connect the BACK wire to 12v from somewhere else and confirm the blue screen and BACK pop up. Wouldn't expect it to have been damaged, as it is used to seeing either 12v or nothing anyway.

[NigelOBB]

Modern wiring is very light you may have burnt a wire out see if you can do a continuity test from relay to end source and the same with boot earth..

[BaroqueMoon]

Ergh ... I will plough on regardless of my ineptitude.
Many thanks for your responses.
Ummm ... How much might an auto electrician be likely to charge to fix this mess do you think. You know, just in case I make things worse :/