Electrical parts

Car electrical parts: how to buy an alternator, starter or sensor

Updated 20 October 2026

Diagnose first, buy later

Car electrics are tricky: the symptom often points to the wrong part. The battery light on the dash does not always mean a dead alternator; sometimes it is the brushes, the voltage regulator or corroded terminals. A starter that only “clicks” can be caused by a weak battery rather than the starter itself. So before ordering an expensive part, check the voltage in the car’s system and the battery, or better still show the car to an auto electrician.

What people look for most

Alternators and starters, relays and fuse boxes, wiring harnesses, coils, sensors (crankshaft position, oxygen, ABS), control units, switches. Alternators and starters are often bought reconditioned: that is normal practice if the seller gives a warranty. Control units and sensors are best bought by part number, because visually identical parts can carry different software.

What to put in your request

• Which part — alternator, starter, relay, fuse box, harness, sensor.
• Model and year — for example, Hyundai i20, 2015.
• Engine — capacity and fuel: 1.2 petrol; the version of the part depends on it.
• Specifications — for an alternator the current in amps, for a battery the capacity and cold-cranking current.
• Part number — from the body of the part.
• Condition — new, used, reconditioned.
• Original or aftermarket — a reputed brand or the car maker’s own.
• City, delivery and budget.

Example: “I need an alternator for a Hyundai i20, 2015, 1.2 petrol, 90 A. No new one available, so I will consider a reconditioned unit with a warranty. I will send the part number from the body. Courier delivery to Kuala Lumpur, budget up to RM 240.”

How to compare offers

After you describe the part in a request, sellers reply in the chat: what they offer, in what condition, for how much and when they ship. The platform shows the offer that is best on content first, with reviews of the seller alongside. Sellers can see where they stand among others, so they often improve their terms. Contacts are hidden, and the “How it works” page explains how everything is arranged.

Compare like with like. For a reconditioned part, ask what exactly was replaced (brushes, bearings, rectifier or starter drive) and how long the warranty runs. For a used one, ask whether it was tested on a bench. Ask for photos of the pulley and the connectors: alternators come with several pulley and plug variants. Be extra careful with wiring and control units: re-soldered or resin-coated contacts are a bad sign.

Common mistakes

Buying by the model name without checking the number and the amperage. Fitting a weaker alternator on a car with heavy loads. Forgetting that a new control unit sometimes has to be coded. If the fault is related to the motor, look at the engine section, and look for other parts among car parts.