240 charging problems

Advice gratefully received on this one! My 1990 240GLT is having a few electrical problems. The battery has recently been replaced. Charging light keeps coming on during driving - usually in the wet, but not always. The problem is usually resolved by a fairly gentle tap with a hammer to the rear of the alternator casing. If I hit the right spot, the lights go out and there's an audible change in engine note.

Presumably I need a new alternator? Or is replacing the brushes likely to do the job? Does anyone have a spare alternator for sale, or can someone recommend a reliable (and cheap) supplier of s/h Volvo parts? I'm based in Gloucestershire.

Hoping someone can help . . .

Adrian

Adrian,
The most likely cause of your problem is worn/stuck alternator brushes and (assuming a Bosch unit) these are easy to get at by removing the two screws which hold the regulator to the rear of the alternator. This can usually be done with the alternator in situ.
A new regulator comes complete with the brushes, but they are available separately and require soldering to fit.
Probably a lot cheaper from a Bosch agent than from Volvo.
Also a very careful check of the wiring connections is a good idea.
Hope this is of some help.
Colin.

Adrian,
For parts you could try Borehams or Malins in Oxford.
I personally use Haynes Bros in Wallingford because they are near my work.
Otherwise one of the bigger motor factors may stock these parts.
Or try www.eurocarparts.com for mail order.
If you don,t have any joy with these parts let me know and I will get them for you.
Colin.

Colin

Many thanks for that advice - I'll let you know how I get on!
Adrian