Use this article if…
Use this if you get no sound from any source through your car speakers (FM, USB, Bluetooth and so on). If your phone pairs but only Bluetooth media is silent, start with Bluetooth connects but no audio.
Quick answer
Most of the time you're muted or turned right down on the MK4, a speaker plug is loose, or your retained factory amplifier isn't waking because the turn-on or integration leads are wrong. Check those before you swap any hardware.
Problem
- You get no sound from your vehicle speakers, on any source or on some sources.
Symptoms
- You get no audio from any source: FM, USB test tone or Bluetooth.
- Or your front L/R is dead while the rear still plays.
Cause
- Your retained factory amplifier isn't waking, or it's missing the right turn-on and integration feeds for your build.
- Speaker plugs are loose, shifted one pin, or shorting at the MK4 harness.
- A software mute is stuck, audio focus is stuck after a bad app, or there's a rare output-path fault once you've ruled out the wiring.
Fix Step-by-step
- On the MK4, turn the master volume up and switch mute off, then play a built-in test tone if your unit has one.
- Cycle the ignition and wait for a full boot before you test again.
- Re-seat every speaker connector to the PVS harness diagram. Make sure no stray strands bridge the tabs.
- If you keep a factory amp, check the turn-on lead and the integration leads match your build sheet.
- Temporarily connect a known speaker to one channel, qualified installer only, to prove the headunit is putting out sound if you're in doubt.
- Still dead after those checks? Rule out power / boot issues and Bluetooth routing.
Notes
- Harness: MK4 power and speaker wires
- Bluetooth shows connected but stays silent: Bluetooth connects but no audio
- Phone projection: Phone won’t pair, wireless CP/AA
- General audio builds: Audio hub
Still stuck? Send us these photos
- Vehicle: model, series and year.
- Screenshot: your MK4 volume level and mute state while a test source is playing.
- Photos: the speaker and multi-plug harness ends at the headunit, latched. Add any factory amp retention module and remote turn-on wiring you can show safely.
- List which sources are silent: FM, USB built-in player, Bluetooth media, and whether they're all dead or only some.
- Amplifier path: factory amp retained, or direct to speaker? Name the retention kit or amp if you know it.