Common causes and typical costs
Prices include parts and fitting at an independent garage. Diagnosis first is worth it: a flat battery and a failing alternator feel identical from the driver's seat.
| Job | Typical UK cost |
|---|---|
| Battery replacement | £90 to £300 |
| Alternator replacement | £300 to £800 |
| Starter motor replacement | £250 to £700 |
| Glow plugs (diesel), set | £150 to £400 |
| Fuel pump replacement | £300 to £900 |
| Crankshaft or camshaft sensor | £120 to £300 |
| Immobiliser or key fault | £100 to £400 |
| Mobile diagnostic call-out | £60 to £120 |
What affects the cost
Nothing at all, no lights
Almost always a flat or dead battery, or a bad earth or terminal connection. Check whether the interior lights and dashboard come on at all.
A rapid clicking
The battery has enough charge for the solenoid but not for the starter. Usually a flat battery, sometimes a failing starter or poor connections.
Turns over but will not fire
The battery is fine, so look at fuel, spark or timing: crank sensor, fuel pump, glow plugs on a diesel, or immobiliser refusing to release.
Starts then dies
Often immobiliser or fuelling. If the car starts and cuts out within seconds, note whether any dashboard symbols flash, and mention that when you book in.
Quick checks before you call anyone
- Are the headlights bright or dim and yellow when you try to start?
- Are the battery terminals tight and free of white or green corrosion?
- Is the car in park or neutral, and is the clutch pedal fully pressed?
- Has the immobiliser or key warning symbol appeared on the dash?
- For a diesel, does the glow plug light stay on longer than usual?
How to pay a fair price
If a jump start gets you going but the car dies again a day later, the battery may be fine and the alternator may not be charging. Ask for a charging system test rather than simply buying a battery. Getting quotes on the tested fault avoids paying for parts you did not need.
Compare local quotesFrequently asked questions
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