Mirror reverse-cam wiring?

[RobFlynn]

A bit of a long shot. New aftermarket head unit going in ASAP (Pioneer AVH-Z9200DAB) and trying to strip out/tidy what's already there.

I have an aftermarket reverse camera with one of those screens that attach over the rear view mirror. The headunit will replace the current screen. I've traced most of the wiring and understand it to a large degree and can see mostly see what I have to do. Two aspects have me a little stumped.

1. This bit I don't get at all – on a relay terminal I have a green "trigger" wire going to the screen unit (self explanatory) but also from the same terminal, a red (presumably +12v) wire going into the phono plug along with the camera feed. The camera itself seems only to have a single black cable into it. Can any explain this to me please?

2. @Absolut5 I have a pink wire that looks to go to beneath the passenger seat (yet to see exactly where) which I expect is wired into the reverse light circuit and is used as a signal to switch on camera/screen. Does this need to go direct to the headunit's Reverse Gear Signal Input, or does the interface to retain the parking sensor display you supplied take care of this too?

Thanks

 

[RobFlynn]

Revised the above. After some sleep and revisiting the wiring there were some errors and omissions.

 

[RobFlynn]

Found this online. Diagram looks similar to part of my wiring. Makes me think I can lose my pink wire and take the red wire from the phono plug direct to the headunit's Reverse Gear Signal Input plug the phono plug into the headunit's Rear View Camera In, and bin off everything else. Could anyone with any experience with this stuff provide some insight?

Thanks

 

[Deaky]

The signal to the reverse light is switched by the BCM. It's not a clean signal and some cameras will belly ache with it. In this instance the reverse light signal is used to trigger a relay to supply a clean 12v supply the the reverse camera. This looks like the scenario you have in your old setup. If you have a new HU with a canbus module that supplies a +12v reversing trigger to the head unit then you can send this down the red wire on the phono plug to the new reverse camera, this saves running two wires. You can then ground the camera locally.

 

[RobFlynn]

Cheers Deaky.

So, assuming that:

• The current setup is as you suspect, and the camera end of things is connected as per the "connecting a backup camera" above (12v & GND in reverse light circuit)
• A canbus module supplies +12v reversing trigger to the head unit

I need to:

• Take the reversing trigger from the canbus module and connect it to the red wire on the phono plug AND to the head unit's Reverse Gear Signal Input
• Disconnect the +12v wire from the reverse light circuit, leaving the ground

If there isn't a canbus module supplying +12v reversing trigger to the head unit:

• Plug phono cable into cam input on head unit
• Attach the headunit's Reverse Gear Signal Input to the relay (swap out the green wire)
• Remove the OLD screens +12v and Ground from the relay

Have I got either of these scenarios right?

Thanks

 

[Deaky]

What is your head unit, can you post a pic and a pic of the quadlock/wiring loom

 

[RobFlynn]

I appreciate you trying to help Deaky.

Head unit – Pioneer AVH-Z9200DAB
Installation guide (page 6) – https://pioneer.b-cdn.net/wp-content/uploads/2019/01/AVH-Z9200DAB-Installation-Guide.pdf
Quadlock/wiring loom – It's at home (I'm not). Can post a pic later.

Unless I can with some guidance just get a multimeter on some of these wires and then connect up accordingly, I think i'm going to have to start pulling more stuff out, trace wires and eyeball EXACTLY what's where, which I really don't have time for at the moment. Head unit destined to sit in its box for another month at this rate.

 

[Deaky]

I assume you'll have a fitting kit like this VW Transporter Double Din Car CD Stereo Can-Bus Wiring Fitting Kit, Fascia, Steering Control

The small black box is the Canbus module. splice your rear camera +12v into the reverse signal output on this. Or if you don't mind the camera being on (ie powered up, not visible on the screen) then connect the camera +12v to the blue white ( usually labeled remote or rem) in the head unit wiring loom.

 

[RobFlynn]

Just:

• Canbus reverse signal output to cam +12v
• Canbus reverse signal output to head unit reverse signal input
• Cam to ground

...and do away with the relay etc, and any existing +12v supply to the camera?

Any harm in the camera been on permanently (with ignition)? Is it likely to fail sooner?

 

[Deaky]

Are you using a fitting kit like I linked to?

 

[RobFlynn]

Unlikely the exact one but something similar. I’ll get everything out again when I get home. Installation looked straight forward when I first looked at it but then gout stumped when the existing cam install was more involved than I thought it would be.

 

[Absolut5]

A bit of a long shot. New aftermarket head unit going in ASAP (Pioneer AVH-Z9200DAB) and trying to strip out/tidy what's already there.

I have an aftermarket reverse camera with one of those screens that attach over the rear view mirror. The headunit will replace the current screen. I've traced most of the wiring and understand it to a large degree and can see mostly see what I have to do. Two aspects have me a little stumped.

1. This bit I don't get at all – on a relay terminal I have a green "trigger" wire going to the screen unit (self explanatory) but also from the same terminal, a red (presumably +12v) wire going into the phono plug along with the camera feed. The camera itself seems only to have a single black cable into it. Can any explain this to me please?

2. @Absolut5 I have a pink wire that looks to go to beneath the passenger seat (yet to see exactly where) which I expect is wired into the reverse light circuit and is used as a signal to switch on camera/screen. Does this need to go direct to the headunit's Reverse Gear Signal Input, or does the interface to retain the parking sensor display you supplied take care of this too?

Thanks

View attachment 206987

hiya

you can do away with the relay and install it as follows-

connect the purple/white wire from the pioneer to the green/black wire (reverse) found at BCM, or wire running along rear ceiling down `b pillar…. But I expect you have a CanBus adapter which will be taking car of it

the pink wire from the pioneer is speed pulse, this again normally is joined to the CanBus adapter or behind speedo

now just connect the cameras red wire to ignition, red wire on pioneer loom. Thin wire next to yellow av plug ( attach to camera red wire and the end that goes to headunit, attach to red on pioneer )

job done , this will give image when reverse is selected and rear view image whilst driving..

 

[RobFlynn]

Thanks Jason and Deaky. I now have everything out in front of me and still none the wiser.

Jason - Your instructions match up with the loom that came with the head unit but not with the adapter you sent me.

 

[Absolut5]

I cannot remember every item I send out lol

the pioneer interface takes care of the reverse feed, all you need to do is connect the red from camera to red on pioneer loom … job done

 

[RobFlynn]

Sorry, I thought I’d been more explicit earlier in the thread about what you’d sent me but re-reading was very vague! Still not sure what you mean about red from camera to red on pioneer loom. Do you mean red from camera to red on adapter loom? There is one there but I’d need to cut into it.

I cannot remember every item I send out lol

the pioneer interface takes care of the reverse feed, all you need to do is connect the red from camera to red on pioneer loom … jo

 

[Absolut5]

Sorry, I thought I’d been more explicit earlier in the thread about what you’d sent me but re-reading was very vague! Still not sure what you mean about red from camera to red on pioneer loom. Do you mean red from camera to red on adapter loom? There is one there but I’d need to cut into it.

There is a red power wire at the camera this needs running and connecting to the red 12v switch feed on the back of the pioneer h/u

call us if you like

 

[RobFlynn]

@Absolut5 Thanks for the help and time on the phone earlier. Much appreciated - top man! Reassuring to know we haven’t got cross-wires (excuse the appalling pun!).