Battery light still on after changed new battery

[M Lam]

Hi,

Recently, my dashboard's battery warning light is on. It only turn on after one minute drive. Car also had steering assistance failure come up and cut out a few times while mid-corner.

I put in a brand new battery (Varta Blue 075 D59 which should be a silver calcium battery). It still the same that battery warning light is still on. 

I did check the battery power cable and alternator belt, they look fine. I also tested the alternator with multi-meter. The read as below:-

1. Before turn-on the car, the reading is 12.35.
2. When I turn on the car, the reading is 13.75
3. When I rev the engine to 2,000 RPM with the lights, radio, and AC on, the reading is 13.85.

So, alternator should be fine as it is above 13? But, it never reach 14 and above.

Any chance the alternator still can be issue? Or anything else can cause the battery light?

Thanks

[stef123]

You have a smart charge fault, the alternator has reverted to a safe voltage. 

[M Lam]

Just now, stef123 said:

You have a smart charge fault, the alternator has reverted to a safe voltage. 

Thanks. What I should do? how can I fix that?

[stef123]

Look at the 3 wire connector on the alternator, usual problem is with one of those wires breaking in the loom. 

[M Lam]

18 hours ago, stef123 said:

Look at the 3 wire connector on the alternator, usual problem is with one of those wires breaking in the loom. 

How about remove the smart charge plug from alternator? Can I test it that with this method to confirm the smart charge having issue?

[stef123]

The proper way to test the signals is with an oscilloscope. 

you will be able to check for battery voltage on one of the pins with a multimeter. 

[M Lam]

On 11/20/2020 at 4:24 PM, stef123 said:

Look at the 3 wire connector on the alternator, usual problem is with one of those wires breaking in the loom. 

Thanks for your suggestion. It is the wire issue. The local garage just used 30 minutes to fixed for £45. Everything is working now 🙂