The alternator failed on my 2007 1.8 petrol Focus yesterday, I had ABS and PS warning lights come on. Then the  battery went completely flat and car had to be recovered home. I charged the battery overnight, started the car and confirmed that the alternator is not charging the battery and is noisy. The ABS light was also still on but I did not take the car out for a drive.

I have got the alternator out today - it is a bit of a pain to get to the connectors but it is off the car now - it is a Denso alternator, obviously needs repairing or replacing.

Are there any common problems with this alternator that would cause the noise as well as the lack of charging? And is the ABS light likely to go out after fixing the alternator or is that a separate coincidental problem that happened at the same time?

8 hours ago, unclesam said:

Are there any common problems with this alternator that would cause the noise as well as the lack of charging? 

It's a while since I had an alternator repaired, but yes, it was noisy. Simply the bearings failed inside the spinny thing that creates the electric LOL

1 hour ago, StephenFord said:

the spinny thing that creates the electric LOL

That has just made me chuckle 🤣 One of the best explanations I've ever heard 😀

 

9 hours ago, unclesam said:

cause the noise as well as the lack of charging? And is the ABS light likely to go out after fixing the alternator or is that a separate coincidental problem that happened at the same time?

I hope that you have disconnected the battery since the main cable to the alternator goes directly to the battery positive.

Bearing failure within the alternator will have thrown the rota out of centre. There is very little clearance between the rota and stator, and this will have most likely caused damage to the stator windings

The ABS light is on because of the very low voltage of the vehicles electrical system. Once you replace the alternator and fully charge the battery the ABS should just reset without the need to do anything.

 

Thanks all; just to come back and confirm the diagnosis and fix.

I got the alternator out and took it to a local alternator and starter motor repair place (yes they do still exist). Before I took the alternator in he said that he already knew it was the rectifier that had blown - very common problem on the Denso alternator. He repaired and tested it the same day. He also said that the failed rectifier does cause a noise to be heard. I have refitted the repaired alternator together with a new belt and it is all good. The ABS light went out almost immediately after driving the car.