Alternator not charging

Alternator not charging

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Discussion

yeager2004

Original Poster:

254 posts

97 months

Wednesday 8th March 2017
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The alternator looks to has given up the ghost on my 2001 VW Polo (battery light on, and only measuring 10v when the engine is running).

I’ve booked it in to the garage later this week as don’t have the time to try and sort it myself but I’d like to be armed with a bit of knowledge before I take it in.

There are no bad noises from the alternator, so I am assuming the bearings are fine. So is there any likely reason why it shouldn’t just be a case of replacing the alternator brushes? (have visions of the garage calling up and saying I need a new alternator).

Worst case and it does need a new one – I had a look at ECP in order to get an idea of the price – they seem to vary massively from the expensive Bosch ones, through to the considerably cheaper RTX and Remy. Surely the Bosch one can’t be worth £60+ premium?

Thanks chaps

GreenV8S

30,437 posts

290 months

Wednesday 8th March 2017
quotequote all
yeager2004 said:
is there any likely reason why it shouldn’t just be a case of replacing the alternator brushes?
It might be the electronic module rather than the brushes - if so, shouldn't be expensive.

yeager2004

Original Poster:

254 posts

97 months

Wednesday 8th March 2017
quotequote all
Thanks. It looks like the voltage regulator and brushes come as a single assembley. I've seen the part online at a VW parts place for £28. Hoping garage is willing to source & fit this part, rather than go for the easier (and probably more lucrative) option of just replacing the alternator.

voicey

2,457 posts

193 months

Wednesday 8th March 2017
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Check the earth before anything

steveo3002

10,648 posts

180 months

Wednesday 8th March 2017
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most places will want to fit a new alternator , but yeah it does sound like a new brush pack would fix it

Penelope Stopit

11,209 posts

115 months

Wednesday 8th March 2017
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Don't take your vehicle to a garage, take your vehicle to a auto electrical specialist that has a workshop where the reconditioning of alternators is carried out
If the brushes are worn out, the slip ring may well be badly grooved and will need skimming in a lathe or will need replacing with a new one (bear in mind that a new slip ring will still need skimming in a lathe so as to centralise it, new slip rings never press on at dead center). A professional person re-conditioning your alternator would also fit new bearings while the alternator is in bits
Have a think about my advice as I am led to believe that a replacement alternator could work out to be cheaper than having your alternator repaired, if this is the case, any garage will fit you a new alternator

M32Guy

62 posts

95 months

Thursday 9th March 2017
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Did you measure 10v at the battery or the alternator?