The electrical section of the MOT is narrower than people assume. It isn't a full electrical health check — it covers battery security and condition, visible wiring damage, the horn, and a specific set of warning lights that must not be illuminated.
The electrical section of the MOT is narrower than people assume. It isn't a full electrical health check — it covers battery security and condition, visible wiring damage, the horn, and a specific set of warning lights that must not be illuminated.
Wiring failures are usually about chafing and insecurity rather than anything not working. A loom rubbing on a suspension component will fail even if every circuit currently functions, because it's on its way to a short.
Here's the electrical wording that comes up most and what's normally behind it.
Battery insecure or leaking
The battery isn't held down properly, or it's leaking electrolyte. A loose battery can move about and short against the bonnet or bodywork, which is a genuine fire risk, and leaking acid damages everything it touches.
Full explanation of Battery insecure or leaking
Electrical wiring damaged, chafing or insecure
A section of the wiring is damaged, rubbing on something, or not properly clipped up. Note that the circuit can still be working perfectly — it's the condition and security that's being assessed, not the function.
Full explanation of Electrical wiring damaged, chafing or insecure
Horn not working or not suitable
The horn doesn't sound, is too weak, or makes a sound that isn't a continuous, uniform note. Two-tone air horns, sirens and musical horns are not acceptable on a road car and get recorded here too.
Full explanation of Horn not working or not suitable
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