Ford Mondeo Alternator: Specs, Fitment & Common Faults

A simple multimeter test confirms whether it's genuinely the alternator — and why some replacement units develop the same fault shortly after fitting.

Illustration for editorial purposes

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OEM Part Number: AG9T-10300-BA (genuine alternator — confirm via VIN) — aftermarket alternators Valeo 440713 / Hella 8EL 015 630-791

Accuracy note: Covers the Ford Mondeo (Mk5 2014-2022) as listed in the UK aftermarket catalogues. Alternators are sold by output (amps), pulley type and plug, and the same model usually has two or three units depending on engine, start-stop and the electrical load of the trim — a 120 A unit on a car built for 150 A will undercharge, and a rigid pulley on a car designed for a freewheel clutch pulley will shred belts. The references below are UK aftermarket catalogue listings for this generation, labelled by brand; many are remanufactured exchange units that carry a core charge until the old alternator is returned. Genuine numbers are shown only where a listing quotes one. Check the amp rating, pulley and plug stamped on the old unit, or confirm via VIN, before ordering.

Alternators (aftermarket)	Valeo 440713 (180 A, freewheel clutch pulley, 6 ribs, 56 mm, reman premium exchange, B+, four-point mounting, L39 position, core charge GBP 50.24); Valeo 440782 (220 A, freewheel clutch pulley, 6 ribs, 56 mm, reman premium exchange, M8, L40 position, core charge GBP 50.24); Valeo 440780 (250 A, freewheel clutch pulley, 6 ribs, 56 mm, reman premium exchange, M8, L37 position, core charge GBP 50.24); Hella 8EL 015 630-791 (220 A, V-ribbed pulley, 6 ribs, 55 mm, new, qualified fitting advised); AS-PL A3524S (220 A, freewheel clutch pulley, 6 ribs, 54 mm, new, PL_2305 plug); AS-PL A3672S (220 A, freewheel clutch pulley, 6 ribs, 54 mm, new, PL_3402 plug); AS-PL A3512S (225 A, freewheel clutch pulley, 6 ribs, 54 mm, new, PL_3402 plug); Ridex 4G1292 (180 A, freewheel clutch pulley, 6 ribs, 54.2 mm, new, integrated regulator, excludes vacuum pump)
Outputs & variants	Outputs are 150 A, 180 A, 220 A, 225 A, 240 A and 250 A, all on six-rib freewheel clutch pulleys of 54 to 56 mm. The 180 A units are the base fitment for the 1.5 and 2.0 TDCi and EcoBlue diesels, 220 to 225 A covers the higher-spec diesels and the EcoBoost petrols, and the 250 A Valeo serves cars with the heaviest electrical demand. The Valeo units are further separated by regulator plug position (L37, L39, L40).
Genuine (OE) numbers quoted	AS-PL A3524S quotes FGN20S052; AS-PL A3672S quotes FG23S071; AS-PL A3512S quotes FG23S072; AS-PL A3524 quotes Valeo 439994.
Fitment notes	Read the amperage off the old unit because the 180 A, 220 A and 250 A alternators look alike and share mountings; renew the freewheel clutch pulley with the alternator; Valeo and Ridex exchange units carry a refundable core charge of GBP 50.24 and GBP 30.14; the Ridex units exclude engines with an alternator-driven vacuum pump.

Confirm the Alternator Before Paying for a Replacement

With the engine running, a multimeter across the battery terminals should read roughly 13.8-14.5V — notably lower readings suggest the alternator isn't charging properly, while readings well above 14.5V point to a failing voltage regulator instead. A whining noise that gets louder when heavy electrical loads switch on is a strong practical indicator worth checking first.

Worth knowing when buying a replacement: Several Ford owners report remanufactured or budget aftermarket alternators developing the same whining noise shortly after fitting, sometimes on more than one replacement unit in a row. A well-reviewed reconditioned unit or low-mileage genuine used alternator is frequently the safer choice.

Ford Mondeo Alternator: Often Blamed on the Battery Instead

On the Ford Mondeo, it's genuinely hard to tell a weak battery from a failing alternator just from symptoms — both produce dim lights, slow starts, and a battery that won't hold charge. That's exactly why so many people end up replacing the wrong part, then returning to the garage a few weeks later.

Before you buy: alternator output rating varies by engine size and trim, particularly on cars with more onboard electronics. Always confirm against your VIN before ordering.

Ford Mondeo Alternator: Watch: Replacing It

🎬 Watch: Ford Mondeo Mk5 Alternator Replacement,,hmmm,,, late for halloween

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Mk5; informal title but on-model

Ford Mondeo Alternator: What It Does

Running the Ford Mondeo's electrical systems and keeping the battery charged while the engine turns over — that's the alternator's role. A properly functioning one means the battery only really needs to worry about starting the car and absorbing occasional spikes in demand.

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Ford Mondeo Alternator: Warning Signs, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Alternator Guide for symptoms to watch for (plus a genuinely useful two-minute test to confirm it's not the battery instead), confirming the right amperage and fitment against your VIN, and which brands are worth trusting.

More Ford Alternator

The same part, covered across other Ford models.