Use this article if…
Use this if there is no sound from any source through the car speakers (FM, USB, Bluetooth, etc.). If the phone pairs but only Bluetooth media is silent, use Bluetooth connects but no audio first.
Quick answer
Most “no sound” cases are volume/mute on the MK4, loose speaker plugs, or - when a factory amplifier is retained - the amp not waking because the turn-on or integration leads are wrong. Check those before swapping hardware.
Problem
- No sound from vehicle speakers from any or some sources.
Symptoms
- No audio from any source - FM, USB test tone, or Bluetooth.
- Or only front L/R dead while rear works.
Cause
- Retained factory amplifier is not waking or missing correct turn‑on / integration feeds for your build.
- Speaker plugs loose, shifted one pin, or shorting at the MK4 harness.
- Persistent software mute, stuck audio focus after a bad app, or rare output-path fault after wiring is ruled out.
Fix Step-by-step
- On the MK4, raise master volume and disable mute; try a built‑in test tone if available.
- Power cycle ignition and wait for full boot before testing.
- Re‑seat every speaker connector per the PVS harness diagram - no stray strands bridging tabs.
- If you retain a factory amp, confirm turn‑on lead and integration leads match your build sheet.
- Temporarily connect a known speaker to one channel (qualified installer) to prove output from the headunit if in doubt.
- Still dead after checks? Rule out power / boot issues and Bluetooth routing.
Notes
- Harness: MK4 power and speaker wires
- Bluetooth shows connected but 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: MK4 volume level and mute state while playing a test source.
- Photos: speaker / multi-plug harness ends at the headunit (latched); 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 - all dead vs only some.
- Amplifier path: factory amp retained or direct-to-speaker? Name the retention kit or amp if known.