# Light Wiring/reverse camera



## Panda_jiujitsu (Dec 29, 2019)

Hello lovely forum members!

just after a bit of help in regards to fitting a reverse camera!

I've managed to get all the cabling through the car and spliced into what I thought was the reverse light wire (blue) and still have no signal coming through the head unit 

here's my rear light harness, and what ive done..










Just after some advice as to the reverse light wire colour, and ideally the earth too mainly so I don't chomp through the wrong thing!


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## droopsnoot (Sep 5, 2002)

As I read the wiring diagram, you seem to be correct, the reversing light wire is sw/bl, which is black / blue.

First things first, with the ignition on, do you get a voltage on that wire when you put the car into reverse? And do you then get a voltage on the far end of your red wire, connected via nasty, nasty Scotchlok connector?

The earth wire is brown, but you should be able to connect that at the front of the car as it all goes to the same place.


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## Panda_jiujitsu (Dec 29, 2019)

droopsnoot said:


> As I read the wiring diagram, you seem to be correct, the reversing light wire is sw/bl, which is black / blue.
> 
> First things first, with the ignition on, do you get a voltage on that wire when you put the car into reverse? And do you then get a voltage on the far end of your red wire, connected via nasty, nasty Scotchlok connector?
> 
> The earth wire is brown, but you should be able to connect that at the front of the car as it all goes to the same place.


thanks for the heads up about the wires  ! and yes lol im well aware how bad the connectors are but I figured its a little less messy if I were to mess up!

I don't have a voltmeter just yet but this will be tomorrow mornings purchase I guess. when you say the earth goes to the same place what do you mean? The front of the wiring has just an RCA with a little light blue wire hanging from the side which i assumed i link to the reverse wire on the rear of the head unit? but does that also earth the wire?


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## LesRSV (Jul 5, 2017)

What kind of head unit have you got, and do you have a pic of the cable end of the camera?


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## Panda_jiujitsu (Dec 29, 2019)

LesRSV said:


> What kind of head unit have you got, and do you have a pic of the cable end of the camera?


The head unit is a JVC KD-X561DBT rear looks like this..










So assuming, camera RCA into yellow input, and the additional wire goes to the purple reverse sensor?

The reverse cam was just from amazon, seems to be much alike others really. Link is 
https://www.amazon.co.uk/gp/product/B079P739B8/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1


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## pcbbc (Sep 4, 2009)

The blue/black wire from the reversing light (which you have the red wire patched into on your first picture) needs to go to the purple/white reverse gear signal wire for the headunit (in your second picture).

What other wires do you have? How are the connected? It would probably help if you draw us a diagram.

There will be an earth wire at the headunit end in the car wiring harness going to the stereo. So if you need 0v there, then there is no need to wire a feed the whole length of the car. However normally you don't need earth at the headunit end for the camera wiring. Usually only required at the camera end, if at all. In which case 0v is the brown wire in your first diagram.


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## LesRSV (Jul 5, 2017)

More questions, where does the red wire from the scotchlok go to? There will be two wires in the power cable from the camera,red/black, did you earth the black wire? If you press the "camera" button on the H/U does the camera come on?


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## ab54666 (Nov 18, 2019)

I think you have/haven't done;

1. Connected the live wire from the camera to the reversing light? (the red wire)
2. You haven't connected the head unit to the reversing light? Therefore your head unit doesn't know to switch to camera.

Firstly, if you press camera on the headhunt does it all work? If so then you just need to connect the Purple/White wire from the head unti to the reversing light.


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## Panda_jiujitsu (Dec 29, 2019)

think I found the issue chaps!

so this morning i wanted to make sure there was power actually going to the reverse light. and turns out...there isn't

checked bulbs and fuses, all good so assuming its the reverse switch that's gone.

getting repaired tomorrow so fingers crossed!


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## Essex2Visuvesi (Oct 22, 2019)

Not wise to use those sctochlock things on a permanent install.
Once you've got it working I'd recommend soldering the joints


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## Panda_jiujitsu (Dec 29, 2019)

Essex2Visuvesi said:


> Not wise to use those sctochlock things on a permanent install.
> Once you've got it working I'd recommend soldering the joints


funnily enough, the chap in the garage I use had said he'd solder for me after fixing the reverse switch


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## droopsnoot (Sep 5, 2002)

Panda_jiujitsu said:


> when you say the earth goes to the same place what do you mean?


The bodyshell is the common earth point, most things earth to that. Lots of things earth to it from their fasteners, so you might not see a separate earth wire for everything. The idea is to save wiring - connect every earth point to the shell, and you only need to run positive wires around the place. (ETA - that applies to the 12v supply, not to negative speaker wires or the like).


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## Panda_jiujitsu (Dec 29, 2019)

droopsnoot said:


> Panda_jiujitsu said:
> 
> 
> > when you say the earth goes to the same place what do you mean?
> ...


ahhhh gotcha! thanks for the advice


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## Panda_jiujitsu (Dec 29, 2019)

ta daaa!










Turns out that it was the switch that connects to the gearbox wasn't plugged in fully?

anyways all done now  Thanks for the help guys


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## Essex2Visuvesi (Oct 22, 2019)

Panda_jiujitsu said:


> Essex2Visuvesi said:
> 
> 
> > Not wise to use those sctochlock things on a permanent install.
> ...


Most auto electricians run screaming when they see those connectors :lol:


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## Panda_jiujitsu (Dec 29, 2019)

Essex2Visuvesi said:


> Panda_jiujitsu said:
> 
> 
> > Essex2Visuvesi said:
> ...


Better ones explain why they're not great and solder them for you free of charge


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## Essex2Visuvesi (Oct 22, 2019)

https://tech.bareasschoppers.com/resour ... onnectors/

A good explanation on why they're not so good


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