BMW E46 Tail Light Not Working or Showing as Faulty in the Instrument Cluster
Why does the E46 instrument cluster report a tail light fault even though the light works?
The cause is usually the boot lid wiring harness. The wires can peel open inside the protective rubber boot, and it is a known typical fault on the E39, E46 and E60 models. The condition of the wires is worth checking inside the protective boot between the boot and the body.
How is the boot lid wiring harness repaired?
The faulty wires are replaced with silicone- or polyurethane-insulated wire or with a ready-made repair kit. The 13-wire kit for the sedan is Vemo V20-83-0004. The power for the number plate light can be taken from another wire, but the light needs a separate earth.
Why does the tail light connector melt or the lights not work at all?
The earth of the tail light connector is undersized, and signs of melting may be visible in the connector. The earth wire can be moved directly to the metal body of the tail light. If none of the tail lights work and the cluster reports nothing, the wire has probably peeled open inside the protective boot.