Hi!

My Mk4 Fiesta (1.3 Endura-E) has picked up an alternator whine. There's no issue on cold start then after 20s of idling this terrible whine gets louder and louder and the alternator starts to get too hot touch.

This only happens when the B+ wire is connected, so I'm guessing either a short/huge load somewhere (haven't found one yet) or the diodes/rectifier are gone.

Battery is good, stock radio etc, and the car's only done 27k miles so almost certainly not the bearings.

Before I just swap out the alternator for another one, is there anything I might have missed that's unique to these Mk4s?

Thanks in advance for your expertise, I've picked up lots of advice here over the years as a lurker so glad to finally post 😄

MB

Sounds like a duff alternator, the whine could be a bearing failure or winding noise from a duff rectifier.

 

7 minutes ago, Hearsepilot said:

Sounds like a duff alternator, the whine could be a bearing failure or winding noise from a duff rectifier.

 

The noise completely disappears when the red output cable (B+) is removed and comes back when it's connected, surely that won't be the bearing unless I'm missing something obvious?

Only just got around to looking at the car properly, decided to change the alternator since that's the most likely culprit I reckon 😐

Can anyone advise where (if anywhere) sell a direct replacement?

I'd rather not get one from a breakers yard or eBay if poss since the car has done so few miles and want to keep everything like new ideally!