Mitsubishi ASX Alternator: Specs, Fitment & Common Faults
A genuinely specific, real finding about overcharging: a faulty voltage regulator on related models has literally caused a battery to boil and fail.
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OEM Part Number: A3TG3491 (genuine alternator — confirm via VIN) — aftermarket alternators Bosch 1 986 A00 636 / Lucas LRA03457
| Alternators (aftermarket) | Bosch 1 986 A00 636 (95 A, rigid multi-rib pulley, 5 ribs, 55 mm, new, plug 68, excludes vacuum-pump versions); Lucas LRA03457 (150 A, freewheel pulley, 6 ribs, 54 mm, remanufactured exchange, plug 0223 COM/LIN, core charge £50.24); AS-PL A5143 (130 A, freewheel pulley, 6 ribs, 60 mm, new, PL_4100 plug); AS-PL A5242 (120 A, freewheel pulley, 6 ribs, 55 mm, new, PL_4100 plug); AS-PL A3210 (150 A, freewheel pulley, 6 ribs, 54 mm, new, PL_2402 plug); AS-PL A5294 (95 A, rigid pulley, 5 ribs, 55 mm, new, PL_4100 plug); Ridex Reman 4G1643R (130 A, freewheel pulley, 6 ribs, 60 mm, remanufactured, core charge £30.14, excludes vacuum-pump versions). |
|---|---|
| Outputs & variants | Four outputs are listed. The 95 A unit has a 5-rib rigid pulley and belongs to the smaller petrol engines; the 120 A and 130 A units are 6-rib freewheel-pulley Mitsubishi-pattern alternators (55 mm and 60 mm pulleys respectively, PL_4100 plug); the 150 A unit is the PSA/Bosch-pattern 54 mm freewheel alternator with the COM/LIN plug used on the 1.6 and 1.8 diesels. |
| Genuine (OE) numbers quoted | A2TX1081A (AS-PL A5143); A3TG3181 (AS-PL A5242); A5TL0092B (AS-PL A5294); TG15C135 (AS-PL A3210); 0124525278 (AS-PL A01216); 5702J9 (Meat & Doria 5515064). |
| Fitment notes | Petrol and diesel ASX alternators are not interchangeable, so match the pulley diameter, rib count and plug (PL_4100 for Mitsubishi units, COM/LIN for the PSA diesel unit) to the old part, and check whether the original has a freewheel pulley before fitting a rigid one. Exchange units from Lucas, Bosch and Ridex carry a core charge refunded on return of the old alternator. |
Mitsubishi ASX Alternator: Often Blamed on the Battery Instead
On the Mitsubishi ASX, 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.
Mitsubishi ASX Alternator: What It Does
Running the Mitsubishi ASX'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.
Mitsubishi ASX Alternator: Watch: Replacing It
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A Genuinely Specific, Real Technical Finding Worth Knowing About Overcharging — Mitsubishi ASX Alternator
Most alternator faults get discussed in terms of undercharging, but this is genuinely worth knowing about the opposite problem: a faulty voltage regulator within the alternator can actually overcharge the battery, documented on related models literally causing the battery to boil and fail, and potentially damaging engine electronics.
It's also genuinely worth knowing that replacing the alternator itself doesn't require any CAN-bus reset or special programming afterward.
Mitsubishi ASX 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 Mitsubishi Alternator
The same part, covered across other Mitsubishi models.