Fiat 500X Alternator: Specs, Fitment & Common Faults
On the 500X, a genuinely useful DIY access technique helps reach the notoriously awkward top mounting bolt when replacing the alternator.
Illustration for editorial purposes
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OEM Part Number: 51993603 (genuine alternator — confirm via VIN) — aftermarket alternators Denso DAN1078 / Hella 8EL 015 637-011
| Alternators (aftermarket) | Denso DAN1078 (120 A, freewheel pulley, 5 ribs, 54 mm, new); Denso DAN1146 (150 A, freewheel pulley, 6 ribs, 54 mm, new); Denso DAN1086 (120 A, freewheel pulley, 6 ribs, 54 mm, new); Denso DAN1121 (120 A, freewheel pulley, 6 ribs, 54 mm, new); Hella 8EL 015 637-011 (120 A, freewheel pulley, 6 ribs, 58 mm, new); Hella 8EL 012 430-891 (120 A, freewheel pulley, 5 ribs, 54 mm, new); Lucas LRA04514 (150 A, freewheel pulley, 6 ribs, 54 mm, reman, plug 0213, COM/LIN and M8 B+, £25.12 surcharge); AS-PL A6707S (180 A, freewheel pulley, 6 ribs, 54 mm, new, plug PL_2305) |
|---|---|
| Outputs & variants | 120 A is the standard fitment for the 1.4 MultiAir petrol and 1.3 and 1.6 Multijet diesels, in both 5-rib and 6-rib freewheel forms; 150 A 6-rib units serve the 2.0 Multijet and 4x4 cars and higher-load specifications; 160 A (AS-PL A6537S, 52 mm) and 180 A (AS-PL A6707S, BV PSH 505.939.180.050) units cover the later 1.0 and 1.3 FireFly petrol and hybrid-era cars. |
| Genuine (OE) numbers quoted | 104211-1180 (AS-PL A6707S, 180 A); 104211-8540 (AS-PL A6364, 150 A); 104211-8660 (AS-PL A6721S, 150 A). |
| Fitment notes | Every reference listed uses a freewheel pulley and all are 54 mm except the 58 mm Hella 8EL 015 637-011 and the 52 mm 160 A unit, so pulley diameter and rib count must be matched to the old unit. Ridex references exclude the vacuum pump. The Hella units are marked for fitting by qualified staff. Only the Lucas reman carries a surcharge (£25.12); the AS-PL A6509PR is exchange without a deposit. |
A Genuinely Useful, Real DIY Access Technique Worth Knowing — Fiat 500X Alternator
If you're replacing the alternator yourself and struggling to reach the top mounting bolt, this is genuinely worth knowing: disconnecting the "dog bone" engine mount and wedging the engine forward slightly, away from the firewall, creates just an extra inch of working space — but that single extra inch has been described as making all the difference when trying to reach this specific bolt on related models.
It's also genuinely worth knowing it's worth briefly running the engine with the auxiliary drive belt removed, if safe and practical, since this rules out the belt itself as the source of a noise you might otherwise blame on the alternator.
Fiat 500X Alternator: Often Blamed on the Battery Instead
On the Fiat 500X, 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.
Fiat 500X Alternator: Watch: Replacing It
shared Small Wide platform with Renegade
Fiat 500X Alternator: What It Does
Running the Fiat 500X'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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Fiat 500X 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 Fiat Alternator
The same part, covered across other Fiat models.