Installation

Where do the MK4 power and speaker wires go?

Use this article if…

Use this when the opening is ready and you are connecting the PVS Toyota loom - constant, ACC, earth, and speakers - to match the supplied diagram. If you have not confirmed dash fitment or boxed parts yet, start with install before you begin; if the unit is completely dead after wiring, go to power troubleshooting rather than swapping wires at random.

Quick answer

Dead screen or dead speakers right after plug-in is most often wrong constant, ACC, or earth versus the PVS LC70 diagram, or a plug not fully latched - follow only that loom sheet and re-seat every terminal before assuming a faulty unit.

Problem

  • You need to connect the PVS Toyota harness to power, earth, and speakers correctly.

Symptoms

  • Harness colours do not match a random “universal” diagram.
  • No response after plug-in.

Cause

  • You are also planning amplifiers or factory amplifier retention, which changes tap points and turn-on wiring.

Fix Step-by-step

  1. Use only the PVS LC70 loom - follow the PVS diagram in the box (see fascia install if the radio is not out yet).
  2. Constant 12 V, ACC, earth to clean metal.
  3. Keep accessory taps fused; do not overload the radio circuit.
  4. Re-seat plugs; no stray strands.
  5. Set conservative amp gains while learning the unit.
  6. No sound from speakers? No audio troubleshooting.

Notes

Still stuck? Send us these photos

  • Vehicle: model, series, year, and cab/body variant if it changes the loom.
  • Photos (wide + close-up): vehicle-side factory connector and the PVS harness labels/colours at the radio end; main plug latched home.
  • Earth: photo of the earth point you used (clean metal, ring terminal).
  • Extras: photos of any factory amp retention, line-output, or patch leads - not just the main quadlock area.
  • Text: what works vs fails after power-up (dead screen, no speakers, both, etc.).

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