# Solved: Wiring expert needed



## nichos (Mar 30, 2009)

Hi,
I installed a rear view camera kit on my car, it works fine but am not sure if the connections are what they should be.

Although the advert fotos give connection Info, I got conflicting info from ventors:-

1. please check the MONITOR other RED ANG BLACK WIRE whether CONNECT WELL WITH CAR POWER or not.
2. The CAMERA RED AND BLACK POWER CABLE NEED CONNECT WITH PARKING LIGHT POSITIVE AND NEGIATIVE too So it can work auto when you parking only
3. I SEE, THE BLUE WIRE YOU CAN CONNECT OR NOT, 
BUT IF YOU CONNECTED, THERE WILL AUTO TURN ON ONCE YOU PACKING

The Blue wire from the monitor, in the fotos, presumably makes rear view to appear if it is connected to the (+) of the reverse light.

The schematic wiring a drew in my fotos shows how I connected it & works OK

Can anybody work out what is the correct way & provide me with a proper wiring diagram? ...thanx .....nick


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## dvk01 (Dec 14, 2002)

I would suggest taking to an auto-electrician to check out & pay the £20 or so they will charge. To make sure that it is impossible to come on when you are driving forwards otherwise it will fail the MOT & the traffic police will do you if they see the monitor lit up while you are driving
The fine for that is about £200 & 6 pts on your licence 

They class a camera monitor in the same way as a TV screen, which is illegal to watch while driving if the driver can see it


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## nichos (Mar 30, 2009)

it only shows rear view the few seconds the gear lever in in reverse, once is moved it goes off.


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## wowzer (Dec 28, 2009)

nichos said:


> it only shows rear view the few seconds the gear lever in in reverse, once is moved it goes off.


Maybe that's all it's supposed to do. Ya know, look where you're driving and all that safe stuff.


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## Drabdr (Nov 26, 2007)

nichos said:


> it only shows rear view the few seconds the gear lever in in reverse, once is moved it goes off.


Maybe it got connected to the brake wires instead of the parking light wires?


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## wowzer (Dec 28, 2009)

Does it work as long as the "gear lever" is in reverse?

What makes you think it's not working properly?


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## wowzer (Dec 28, 2009)

Drabdr said:


> Maybe it got connected to the brake wires instead of the *parking light wires*?


 I assume you mean the reverse / back-up wire.


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## buffoon (Jul 16, 2008)

To recapitulate what dvk01 and wowzer are saying: camera and monitor should ONLY work when the gear is reverse. All other positions, including neutral, should turn her off.

The instruction manual appears to be from somewhere where English is probably not the primary forte, so presumably "parking lights" are getting somewhat confused with reverse light.

I'd follow dvk01's advice and put it to an auto-electrician. That way you'll also be sure that everything, installation included, is legit.


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## Drabdr (Nov 26, 2007)

wowzer said:


> I assume you mean the reverse / back-up wire.


Yes.


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## Drabdr (Nov 26, 2007)

Contact the mfg. of the camera and have them provide a wiring matrix for your vehicle.

Also, if you could be more specific about exactly when the camera comes on and goes off, that would help us.


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## nichos (Mar 30, 2009)

In this installation rear view shows when the gear lever is in reverse.

It owrks OK, just thought it would be nice to have a proper wiring diagram.

Mfrs are in Chine & can not be contacted.


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## Drabdr (Nov 26, 2007)

nichos said:


> In this installation rear view shows when the gear lever is in reverse.
> 
> It owrks OK, just thought it would be nice to have a proper wiring diagram.
> 
> Mfrs are in Chine & can not be contacted.


Yea. I know what you mean. Sometimes it seems impossible to get the appropriate information you need.

If you feel this thread has been answered completely, please click on the button to mark the thread "solved". Thanks for checking back in on it. :up:


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## Macboatmaster (Jan 15, 2010)

nichos
I appreciate that you appear content that all is now OK
However I am not sure.
It is difficult to advise you properly as I have no spec for your system, but looking at your wiring diagram - as such I think you may have problems

YOU appear to be drawing all power +12v from the reversing light - at least that is what your diagram shows

You cannot do this the demand on current again depending on your specs for the reversing camera system will overload the fuse for the lights

The first line of the poor english instructions


> please check the MONITOR other RED ANG BLACK WIRE whether CONNECT WELL WITH CAR POWER or not


refer to the now more or less obsolete idea, as far as the UK is concerned of the old + earth system vehicles, rather then the now accepted arrangement of +12v to supply and - to earth

You connect the red wire to an ignition live in otherwords one that is ONLY live when the engine is running and the black wire to an earth

YOU then connect the blue wire which is a swtiched live to the + of the reversing light
Although the guide below is generic, it will I am sure be the same in principle.

Provided with the monitor are the Power (red), Reverse (blue), and Ground (black) wires that need to be connected. The ground wire should be connected first. To do this simply locate a solid chassis ground and secure the wire to it. Second should be the power. This should be connected to a post ignition power source and connected with the 5 amp fuse and wire provided (see the monitors operation guide for the voltage requirements). Last will be the reverse wire which should be connected to the reverse light circuit. When connected properly this allows the system to come on when the vehicle is placed in reverse


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## Drabdr (Nov 26, 2007)

Macboatmaster said:


> nichos
> I appreciate that you appear content that all is now OK
> However I am not sure.
> It is difficult to advise you properly as I have no spec for your system, but looking at your wiring diagram - as such I think you may have problems
> ...


:up::up:

I did not even notice the diagram attached. 

The four block in the middle. Is that a terminal block that had been added for this project? Or is that a fuse block?

You make a good point about the amperage, Macboatmaster. The wire to the reverse light is fused somewhere; probably at the source feeding it. The fuse is sized accordingly, and should not be arbitrarily increased as it may affect other things (conductor size for one).

Powering the monitor with a wire from the post ignition source (and fused accordingly) is the best method.


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## Macboatmaster (Jan 15, 2010)

Cheers
To be honest, although I have looked at the diagram, unless I am misreading what I see, I cannot follow the idea behind it

As the earth system - appears to come from the battery and what is labelled air pump. The live +12 to the pump is a switched live, but unless it is some very unusual set up and I have a little knowledge of car wiring systems - the earth is constant whatever the position of the switch.

That is so generally of course unless you have a switched earth, such as in a courtesy light, operated on the door pillar switch, where the live is constant and the light is operated either ON/OFF or courtesy, when it is a switched earth from the door swich

What certainly appears to be the case, is that as the red and blue wire are connected to the same supply source - the reversing light and indeed the +12 to the monitor as well - it is NOT CORRECT


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## nichos (Mar 30, 2009)

Thanx all again,

I have revised the installation & my bad drawing as per attached.

No way can I brake into the Ign.S/W or any other wiring except the simple pickup from the reversing lamp (parking lalmp to some?). The car is a 2011 Benz A Class Autom. & too sofisticated for me.

Now the Camera & Monitor (+)ve plus the blue cable go directly to the (+)ve reversing lamp.

The two (-)ve wires are Earthed directly to the chassis (via seat securing bolt).

Rear view shows, ie system powered, ONLY for a few seconds when the gear lever in in reverse.

Do you think this away the electrics will be overloaded? Please scrol all the way down to see the full specs here:- http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120956549024 .....nick


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## Drabdr (Nov 26, 2007)

Nichos can you find out what size fuse is feeding the light?

I agree with Macboatmaster, that is too much on that circuit. Is there an open (maybe a spare) on your fuse box for the vehicle? There should be the ability to pick up a + from the battery (and/or ignition-switched) from there.


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## nichos (Mar 30, 2009)

The car fuse info shows Rev.Light as items 18 & 70. Please see attached.

Item 18 is 7.5A & item 70 is 60A

Which one is now?

Even if there is a spare fuse no way can I connect & pull a cable from in there.

The specs I gave in my last post say first at the top "...power consumption 6W.." & towrds the bottom "...Current Consumption: No More 300mA...." for the Monitor & for the camera respectively.

The camera booklet says :-Current Consumption 50-60mA Max 300mA with IR on. (perhaps at night?)

The Monitor booklet says:- Consumption 6W

They mean nothing to me, would they be overloading the electrics for those few seconds in use? ....nick


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## Drabdr (Nov 26, 2007)

BTW, I like the way you provide pictures and links. :up:



nichos said:


> The fuse info shows Rev.Light as items 18 & 70.
> 
> Item 18 is 7.5A & item 70 is 60A
> 
> ...


I'm pretty sure the lights are on the 7.5 Amp. The easy way to tell is to pull the fuse (at home) go in reverse and see if the lights don't work. I would think that 60 amp fuse powers a more involved system of some kind.

If the Ebay link has the same specifications as the unit you have, it is listed as 12 volts/ 6 watts; which means it will pull about .5 amp. The key is how much is already being pulled on that fuse. Depending on the wattage of your rear bulb (and any other ancillary relay/ check system powered from that circuit), that may push it over the edge. It's really hard to tell.

does your vehicle have a cigarette lighter or power port of any kind in the back? Those are high amperage/ low usage circuits that you could use to power the device.


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## nichos (Mar 30, 2009)

In the full fuse info attached the item 18 only refers to Rv.Light & does not appear on another circuit.

The bulb itself says 12v/P21W

Adding to this, the kit's Watts & MAmps does it sound too much?


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## Macboatmaster (Jan 15, 2010)

The instructions may be poor, but I really do not understand the problem
I hope that does not sound insulting, as if you do not know anything about wiring I can see the diffculty

1. You do not have to break into any ignition circuit at the switch 


> No way can I brake into the Ign.S/W or any other wiring except the simple pickup from the reversing lamp


You simply choose a wire that is ONLY live with ignition on - that is so as to ensure that the monitor and or camera cannot be ON when the ignition is OFF, eg the car parked

The camera is dual purpose, you may either switch ON and use it as a rear view camera WHEN NOT reversing
I would not recommend that you strap the *monitor* across the rear view mirror - in the UK that MAY be illegal - depending on the image seen in the monitor when it is acting as a mirror eg NOT switched on.

The image on ebay, is even if the instructions are clear as mud - very clear
I have attached the screenshot

It is EXACTLY as it says 
red wire to +12V - if you know that you will never leave the equipment on in error then you may choose any wire depending of course on where it is to and from.

If you connect it to a live on running source only, then it CANNOT BE ON when the ignition is off and the car parked

The blue wire is a switched live which switches the equipment on when you select reverse gear and the reversing light is on

That is WHY it says you may or may not connect.

If you do connect to the reversing light or a position on that wire, not necessarily at the light, then it will be switched on auotmatically


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## wowzer (Dec 28, 2009)

I don't know the vehicle but there should be a fuse panel under the dash somewhere that will have a spare /aux space, for lack of a better word spot, that is only live when the ignition is on to connect the red to. simple to test that.


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## nichos (Mar 30, 2009)

As I mentioned earlier the car is a 2011 small Benz A Class.The fuesebox is in a floor hatch under driver's feet, it does not seem to allow adding cables. & if added they will run under the box inside the shassis's inaccessible loops. The whole of the car underside is covered with pannels.To an old octogenarian the simpless way is as per last wiring attachment, take power from the rear reversing light.From the figures given can anyone tell if it overloads the reversing light wire? ........nick


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## Macboatmaster (Jan 15, 2010)

No it will not overload the circuit.
Amps are watts divided by volts. 
Therefore 21 watts is 1.75 amp. If you have two reversing lights it is 3.5 amp.
If the total power demand for the equipment is 6 watts that is .5 amp.
You do not need, as I have already said to concern yourself about connecting direct to a fuse carrier, or to the ignition switch.
You simply connect to a wire that is live only when the ignition is on. The cigarette lighter mentioned by my colleague is a common example.
The black wires on your equipment can be connected to the same earth - any earth.
You then connect the blue wire to the LIVE terminal of the reversing light.

That all said, it is not wired as it is meant to be wired, but as it works and appreciating the difficulty - you may wish to leave it as is.
IT will not, on the evidence to hand overload the circuit


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## nichos (Mar 30, 2009)

Very kind of you , thanks for your patience and all the others who helped.

I am very grateful as we find it a very useful aid. .........nick


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