Use this article if…
- You're adding a front or extra camera and assigning inputs, not diagnosing reverse on its own.
- If reverse and front priority are the wrong way round, see Multiview switching. If you're on an MK4, see MK4 cameras.
Quick answer
If your front plus reverse setup fails, it's usually because the coax runs aren't labelled or you haven't set reverse priority. Assign each physical input in the headunit menu, and label your plugs before you route them. Then shift from Park to Reverse with the vehicle stationary to prove the switching works.
Problem
- You're adding a front or second camera alongside reverse on the headunit.
Symptoms
- You get the wrong input after the install.
- Your cameras fight over the same trigger.
Cause
- Input priority, reverse override or the last source rule on your headunit conflicts with the way you assigned the front and aux inputs.
Fix Step-by-step
- Write the camera map first. Note which physical port is reverse, front and side, then decide what wins when you engage reverse. Usually reverse overrides everything.
- Tag coax before it disappears. Label both ends REV, FRONT and AUX before you route through the firewall, bull bar or headliner. Common mistake: four identical black RCAs and guesswork at the radio.
- Power deliberately. Front may run off ACC plus a manual button, reverse uses the +12 sense. Don't strap two different triggers to one lead because it worked once.
- Headunit menu pass. Assign each input, set the reverse source, then enable front from the icon or the steering wheel if it's supported. Screenshot the settings for later.
- Park test sequence. Chocks in, brake on: open front view, then shift to reverse. Reverse must take over. Roll forward and confirm front times out as the manual says.
- Route for heat and steer. Leave a service loop at the grille for bar-mounted front cameras, and keep coax off the exhaust and the steering column.
Real-world conflicts
- Your front camera stays powered live while you reverse, so the software never hands over to reverse.
- If a side camera shares the reverse input through a Y-adapter, your headunit sees one confused stream.