Audi S5 Battery Light on – Here's What We Found

From Warning Light to Full Alternator Failure

This Audi S5 came into our car garage in Newtownabbey with the battery warning light illuminated on the dashboard. As with all electrical faults, our first step was a proper charging system check.

The alternator was only producing 10.8 Volts, far below the expected range of 13.5–14.5V. That alone told us something was seriously wrong.

We removed the alternator belt and found the root cause:

• The alternator bearing had completely collapsed: a failure that can lead to seized pulleys, snapped belts, and battery drain.

What the Alternator Does (And Why It Matters)

The alternator is a vital part of your car’s charging system. It keeps the battery topped up and powers the electrics while the engine is running — from your lights and wipers to your ECU and safety systems.

If your alternator fails:

• The battery won't charge

• Warning lights will appear

• Electronic components may flicker or stop

• Eventually, the car won’t start at all

Collapsed bearings like this one can cause the alternator to grind, seize, or shred the auxiliary belt — leading to even more damage under the bonnet.

Symptoms of a Failing Alternator

Here’s what to watch out for:

• Battery light on the dashboard

• Battery going flat more often

• Headlights dimming or flickering

• Electrical accessories cutting out

• Whining, grinding, or burning smell from the engine bay

This customer noticed the warning light just in time. Had they ignored it, the belt could’ve snapped or damaged other components like the power steering or water pump.

Expert Charging System Diagnostics – Belfast & Newtownabbey

At 1Stop Motor Shop, we don’t just guess — we test.

• Voltage output checks
• Belt and pulley inspection
• Bearing noise diagnosis
• Alternator and battery replacement
• Fast turnaround & trusted service

Whether you drive a performance vehicle like an Audi S5, or a family car with electrical faults, our experienced team will get to the root of the problem quickly.

Get It Checked Locally in Newtownabbey or Belfast

If you're in Newtownabbey or Belfast and notice any of the signs above, book in with us at 1Stop Motor Shop. We'll diagnose the cause of your coolant leak and carry out fast, affordable repairs to keep your car running safely.

Trusted by drivers across Belfast - how to contact us:

- Call/WhatsApp (phone and text): 07951 728365
- DM our socials (Facebook & Instagram)
- Email: OneStopMotorShop@hotmail.com
- Contact us via our website