2021 Ford Transit 350 Leader Ecoblue 2.0L Diesel · WN71 OLP

A recurring pattern of rear lamp and electrical defects dominates the MOT history of this 2021 Ford Transit 350, with three of the four recorded tests containing failures or advisories linked to lighting circuits. The most recent test on 20 October 2025 was a pass, but only after the vehicle had failed just one week earlier on 13 October 2025 with four major defects, all relating to rear direction indicators, the nearside stop lamp, and the rear fog lamp being adversely affected by the operation of another lamp. This points to a likely shared wiring, earth, or bulb holder issue at the rear of the vehicle rather than isolated component failures. The 2024 test record reinforces this concern, showing a dangerous rear tyre, a faulty wiper, and a defective side repeater in December, followed by an earlier failure in October 2024 for non-functioning rear stop lamps and lower position lamps on both sides. The repeated lighting-related advisories and failures across consecutive tests suggest an unresolved underlying electrical or earthing fault rather than a one-off bulb failure. With 89,260 miles recorded on a 2021 vehicle, this Transit has covered approximately 17,850 miles per year, which is high for its age and consistent with commercial or heavy fleet use. This level of annual mileage places elevated wear demand on braking components, suspension bushes, coil springs, drivetrain mounts, clutch and dual-mass flywheel assemblies, and turbocharger service items. The fact that the vehicle has been tested regularly with relatively short intervals between attempts, including a failed test followed by a retest only seven days later, suggests it has remained in active service rather than being laid up, but it also means any remedial work was carried out under time pressure to clear the MOT. For a prospective buyer, the priority on inspection is the rear lighting loom, earth points behind the rear light clusters, and the condition of the bulb holders, which should be checked for heat damage, corrosion, and loose fitment. The nearside front wiper linkage and motor should be tested for effective clearing across the full sweep, and the side repeater lens examined for cracks or water ingress that could mask an MOT failure. The nearside rear tyre, which was flagged as dangerously below tread depth in December 2024 and previously as worn on edge, warrants close inspection of the rear axle geometry, tracking, and any uneven wear pattern that could indicate a worn beam arm, trailing arm bush, or suspension knock. On a test drive, listen for clonks or knocks from the rear suspension over speed humps, check for any steering pull or wandering that may suggest geometry or spring fatigue, and verify that the instrument cluster display functions correctly, noting the cracked screen advisory which may eventually affect readability of warning lamps and the digital speedometer. Given the high annual mileage and the cluster of electrical and lighting faults, any prospective purchase should be accompanied by a thorough undertray and rear wiring inspection, ideally on a ramp, to confirm the integrity of the rear lamp circuits and to check for oil leaks from the rear of the engine, gearbox, and differential seals, all of which are common wear items on high-mileage Transit derivatives. A diagnostic scan for stored fault codes, particularly within the body control module and lighting systems, would help identify whether the repeated rear lamp failures are symptomatic of a deeper communication or earth fault. The brake discs and pads, including the rear caliper slide pins which are known to seize on Transits of this generation, should be physically inspected for wear and free movement, and a cold start should be observed for excessive smoke or rough running that could indicate turbo or EGR issues associated with sustained high-load use.