Auto Electrical Service
Alternator Services
Charging system testing and repair to protect your battery.
Your alternator keeps your battery charged and supplies electricity to every system in your vehicle while the engine is running. When it fails, you may have 30–60 minutes before the battery goes flat completely. Mobile Auto Elec provides same-day alternator diagnosis and replacement across Johannesburg.
Warning Signs
- Battery warning light on dashboard
- Dim or flickering headlights
- Electrical accessories behaving erratically
- Battery draining repeatedly despite recent replacement
- Whining or grinding noise from engine bay
Our Process
We test the full charging system: output voltage, ripple voltage, and load capacity. This identifies exactly whether the alternator, voltage regulator, diode pack, or drive belt is the cause. Most alternators are replaced on-site in 1–2 hours. Reconditioned and new units are available for most vehicle makes.
Frequently Asked Questions
The most common signs are the battery warning light appearing, dim or flickering lights, electrical accessories acting strangely, and a battery that keeps going flat even after replacement.
Yes. An undercharging alternator will gradually drain your battery. An overcharging alternator (above 14.8V) will overheat and destroy a battery within days. Both conditions need to be fixed promptly.
Typically 100,000–150,000 km under normal conditions. In Johannesburg's heat, expect the lower end of that range. Vehicles with high electrical loads (bull bars with many lights, sound systems, fridges) put more strain on the alternator.
Always. We never replace parts without confirming they are actually faulty. A full charging system test costs nothing extra and ensures you only pay for what you actually need.