Contacteur de batterie défectueux

One of the heavy relays that connect the traction battery failing at its job — a coil that no longer pulls in, contacts worn or burnt until they carry current badly, or a mechanism gone lazy with age. The welded variant has its own entry; this one covers everything short of it.

The contactor is the last suspect on its own codes, not the first. A contactor needs a healthy twelve-volt supply to close, an intact command wire to be told to, and a working feedback circuit to be believed — and all three fail more often than the relay itself. The stuck-open presentation (a car that will not wake) starts at the twelve-volt battery and the service plug; the contactor earns its place at the end of that list, partly because replacing it means opening the battery pack, which is qualified-workshop territory with a bill to match.