Factory rear view screen to use two cameras

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

sorry haven't checked the thread for a while. no I haven't tried it yet, haven't had time !
I have the camera, just need to pull my finger out. will buy a switch and attempt to do what Tin175 did.
Tin do you have a wiring diagram by any chance ? just wondering what the relays are for and how they're wired up ?

Thanks !

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

I've drawn up what is probably a very dodgy circuit

but this uses a diode, which Tin hasn't referred to so far.
Can anyone with a bit more electrical knowledge than me have a look and let me know if you think this would work ?

Thanks !

[Tin175 Senior Member Find all posts View Profile Close Tin175]

I did use a diode in my circuit.

Your wiring diagram looks good to me.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

thanks Tin. so does the diagram look like what you did ?
any experts that can have a look and maybe simplify the wiring to do the same thing ?

thanks, looking forward to doing this soon on a facelift 150 GXL !

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

updated circuit for those playing along at home.
I've been advised that as the relays i'm using are resistor protected and not diode protected, I need to add a diode across the coil of each relay.
So, below is the updated diagram.
The diodes are all part # IN4001 and the relays are both Narva 68044BL changeover relays.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

updated circuit for those playing along at home.
I've been advised that as the relays i'm using are resistor protected and not diode protected, I need to add a diode across the coil of each relay.
So, below is the updated diagram.
All 3 diodes are # IN4004 and the relays are both Narva 68044BL changeover relays.


I've also added the relay terminal #s which are standard across all manufacturers.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

OK some progress. Have implemented the switch and first of the 2 relays. So I can now manually switch the camera on. Working well so far !
Pics to follow showing the plugs and some of the wires used.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

Bottom part of centre console removed to show bolts that need to be removed so stereo unit will come out.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

Once the 4 bolts from the picture above are out the whole unit will just pull forward.
Picture of stereo unit pulled out.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

Photo of rear of stereo unit so you can see all the plugs.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

I found the reverse signal in this plug.

Wire cut ready for diverting.

[Hollywood Member Find all posts View Profile Close Hollywood]

Just came across this thread, what's the purpose of the diodes on the relays?

[MacroP Member Find all posts View Profile Close MacroP]

Just came across this thread, what's the purpose of the diodes on the relays?

They are flyback diodes. Some automotive relays come with these integrated now. When the relay is turned off the diode stops a voltage spike from the relay's coil due to the collapsing magnetic field of the relay's coil (though very small). This spike could harm connected electronics. The diode short circuits this potential spike as the polarity of this spike is in reverse to the previously applied voltage.

Just note that if you get an automotive relay with an integrated diode - note that the relays are polarised - you have to connect the negative and positive to the relay's coil correctly. Some automotive relays have a bleed resistor instead across the relay's coil and work (protect) in a similar way but are not polarised. A regular automotive relay is not normally polarised.

[Hollywood Member Find all posts View Profile Close Hollywood]

Thanks for the info.

[Hollywood Member Find all posts View Profile Close Hollywood]

maulbeagle - I redrew your schematic on some free software I found. I moved the relays around and swapped the switch positions so up is the front camera and down is the rear, hope you don't mind. Otherwise it should be the same as your setup. (Ignore the actual switch position with regard to what the relays are doing, I can't change the switch position.)