wiring a reverse camera: retrofit Android auto over-dash screen

Getting an Android Auto / Airplay add-on screen for a old car is possibly the best upgrade you can do for the smallest money. I’m impressed by the 9 inch unit I bought for a VW Golf Mk5 – it’s powered by USB such that when the car turns on it recalls the Bluetooth connection with your phone and then mirrors what it can do ie deliver maps, navigation, make calls, play music and radio. Below I record how I connected it up adding the tricky step of wiring a reverse camera. The result is such that popping into reverse gives a helpful image of what’s going on back there. I’ll leave it to others to help you choose a ‘good’ unit – just know that for me the key attributes were quality and completeness (Eonon); suitable USB / cigar lighter power options; car audio output options; appropriate dashboard mounting for your car and importantly having front and rear cameras. Do also consider going for the complete console radio unit replacement – I didn’t because of the scale of the installation involved – however this really transforms the car.

you will need

• display unit kit allowing for mounting; audio output; power input*; camera/s; phone with data connection (most are compatible)
• a USB power cigar lighter may come with the kit
• small T-tap connector for reverse light trigger wire or wiring skills; insulation tape
• self tapping screws to fix camera

getting the Android Auto/Carplay unit installed

In car test: power the screen with a USB lead; pair to your phone (which if reasonably new will not need an app); connect the screen to the car audio system: I chose to tune a car radio station button to the device’s radio frequency output but wiring in is possible as long as you get a device that suits your car’s wiring.

If you’re top mounting it on the VW Golf Mk5, you’ll need a video to see how to partially disassemble the dashboard to route the wiring out of sight. The video below shows how to to do this and more. In my case:

• remove two torx screws from the top dashboard tray after removing the small mat. Use a pry tool to gently remove the plastic tray AND the large curved plastic surround for the air vents. Use the video to identify where to use the the pry tool.
• feed the main USB power lead from the front centre cigar lighter up through glove box (slot at back on the right) up to the top dashboard tray. feed the reverse camera wire on this path too. It’s tricky but a coat hanger wire / stiff wire may help.
• Pull the USB power lead downwards behind the glove box and use the pry tool to feed it under the dashboard console cover towards the cigar lighter socket.
• The reverse camera lead will have a connector nearest the camera end. Separate the camera connector so that you can install the camera from the rear inwards leaving you to run the headunit lead from the dashboard, along the car towards the tailgate as follows. Pop-off the triangular dashboard cover that faces the door. Pull the reversing camera lead this way and route it at floor level all the way to the back seats. At the back seats you’ll want to remove the lower panels on the left side of the boot. Start by popping off the central main cover for the boot lock; this should expose a torx screw and a felt tab plastic rivet on the left to remove. Still on the left go to the top of the rear seat belt and pry off (from the back end) a discrete cover. Remove the torx screw here. After removing the lower plastic covers you should now be able to peel back the boot felt on the left. Now continue to route the reverse camera wire from the back seats to the tailgate lock.
• My camera was fitted between the licence plate lights as flush to the bumper as I could. I didn’t drill holes because I found a central hole to feed the reverse camera and its loose camera wire towards the left wheel arch wiring loom. To help I removed a license plate light – press its tab on the right to remove it downwards. Your camera fixings will vary but in my case I used gel tape and a couple of self tapping screws into the plastic – screwing upwards. I moved my number plate down 20mm for this.
• At the left wheel arch a bundle of wires connect with the reversing lights on the actual tailgate. The tailgate wires are white and a (probably hidden) plug routes and connects them as a bundle with their useful colours. Look for a blue-black wire (blue with a black stripe) – this is the reversing light positive. Use a T-tap connector to splice the camera trigger wire onto it. You might want to verify it’s the correct wire as in the video below.
• With luck you can now turn on the ignition, pop into reverse and see the rear view with the green/red parking lines! Remember to calibrate the lines using settings on the main device.