Alternator Replacement Cost UK
See how much alternator replacement typically costs in the UK. Our estimates are based on manufacturer labour standards and current parts pricing across budget, mid-range, and OEM tiers.
Alternator Replacement Cost Estimate
Based on UK average labour rates • Standard Car
Typical Total Cost
£194 – £754
Labour
Low
1.5h
≈ £114
Average
2.5h
≈ £190
High
4.0h
≈ £304
Parts
Cost by Vehicle Make
Premium makes typically cost 20-30% more due to complex engineering, specialist tooling, and higher parts pricing.
Premium Brands(9 makes)
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When Is It Needed?
Alternators typically last 100,000–150,000 miles, but can fail earlier due to heat stress, worn bearings, or electrical faults. There's no set replacement interval — alternators are replaced when they fail or show signs of imminent failure.
Labour Time
Alternator replacement typically takes 1–2.5 hours. Access varies significantly between vehicles — some alternators sit on top of the engine and take under an hour, while others (especially transverse engines) require removing multiple components for access.
Warning Signs
- •Battery warning light on the dashboard — the most common first sign
- •Dim or flickering headlights, especially at idle
- •Electrical systems becoming sluggish — slow windows, weak air con blower
- •Whining or grinding noise from the engine bay that changes with engine speed
- •Battery keeps going flat despite being recently replaced or charged
What's Involved in the Repair?
- 1
The auxiliary drive belt is removed to access the alternator
- 2
The electrical connections (main power cable and plug connector) are disconnected
- 3
The alternator mounting bolts are removed and the unit is extracted from the engine bay
- 4
The new or remanufactured alternator is fitted and bolted in position
- 5
Electrical connections are reattached and the drive belt refitted and tensioned
- 6
The charging output is tested to confirm the new alternator is functioning correctly
Expert Tip
When fitting a new alternator, have the battery tested too. A failing alternator can damage the battery through overcharging or undercharging, and a weak battery can shorten the life of a new alternator.
Frequently Asked Questions
What are the signs of a failing alternator?
Dashboard warning light (battery symbol), dim headlights, electrical issues (windows moving slowly), whining noise from the engine bay, and a dead battery despite being recently replaced are all common signs.
Can a bad alternator damage my battery?
Yes. A failing alternator can undercharge or overcharge the battery, both of which shorten battery life significantly. If your alternator fails, have the battery tested before fitting a replacement.