Hi folks.
Driving along then 'ping', on comes the battery light.
Replaced the battery. Replaced the alternator. Nothing has fixed it.
Used a local garage diagnostic machine to clear all codes. Of which there was none.
I've checked all the fuses in both fuse boxes. All where good.
Only extra I can mention is the radio is dead. So far I can see anything else that isn't working. If I do, I'll post.

Does anyone have an idea what might be at fault?

 

That battery light comes on when the battery voltage drops below 12V. If your engine is running and this light comes on then your battery isn’t retting any power from the alternator either because the alternator isn’t working and generating power, that’s usually the issue. It can also be because the power isn’t reaching the battery from the alternator.most shops will check your battery to make sure it’s capable of holding a charge and then check the voltage at the battery cables to verify it’s getting a charge from the alternator either, if it’s not then they check at the alternator to see if it’s making power. This way they know what needs to be repaired. It seems in your case the didn’t check anything and just started selling you parts. The other component that could be the problem and it doesn’t sound like it was tested is the battery cables, if there is a damaged cable or highly corroded cable then that would also cause your problem. A good tech should be able to isolate the problem and run a replacement for you. If it's not resolved soon your going to end up stranded in the near future. If that happens you will need to get the battery charged, a quick jump start will only get it running briefly. Might as well get it fixed asap, it'll be a lot cheaper than getting it towed.

 

Thanks dwood.
So far I've replaced the alternator and the battery.
Checked all connections and cables.
Checked all the fuses in both fuse boxes.
Checked the earth straps from the engine.
Appart from the battery light, the only other fault is the radio being dead.

I'm going to try working back from there. (In a week)

 

So the car drives fine and recharges the battery without dying?

 

Yes Racer. Everything so far works ok with just the radio being dead.
There maybe other things that I haven’t found yet.

 

is the voltage regulator inside the alt or separate.

 

Pit it’s in the alternator

 

Get a multimeter and start checking voltage at the battery and alternator and verify that it’s above 14V when the cat is running, somewhere the voltage isn’t correct,

 

go to youtube lots of people with same problem different makers and oh so many different fixes..

 

Hello again guys.
Just want to report the fix.
As you may know, normally the main problem with the battery light is the alternator. This was the first thing I replace.
While waiting for a new alternator I replaced the battery, but this didn't fix my issue.
New alternator arrived so I got it fitted. Still had the battery light on.
This really puzzled me because the battery light is usually direct from the alternator. I was thinking perhaps nowadays it takes a different path. Possibly threw an ECU.
So after tearing my car to bits to access just about every electrical component........ I found the bloody 'NEW' alternator was faulty. AAARRRGGGHHHH

Fitted a second 'NEW' one. Now all is well.

Thanks for your input folks.

 

With the alternators generally being refurbished, this is good to know.

 

things like that are a PITA especially if the alt is hard to get out. glad it worked out.