2005 td4 alternator

Morning one and all
I'm having alternator issues and would like your thoughts
battery light flashing on and off for a few miles then on all the time
12.4v on the battery cleaned all the connections .... light still on
hit alternator with a bar and hammer ..... engine revs drop and charging at 14.06v
runs fine for 10 minutes or so then battery light on again .So to me that would suggest alternator is on its way out , so thought sod it and filled it with wd-40 not sure if that was a good idea or not but time will tell and all seems ok so far , could i be right(ish) in thinking the brushes are probably worn out ? the old girl has done 131k miles and as far as i'm aware its the original alternator

hi

take it down to halfords etc and they can test it for u

hitting it with a hammer might have not done it any good, lol

could also be a loose wire or bad connection , assume the belt is ok

check the amperage when replacing as there's different models

meant to say , should never spray anything electrical with wd40 as its highly flammable, could have caused a fire and also can make the belts slip

I would think your prognosis is close to the facts.
Brushes probably worn out.

thanks for the replies
looks like wd40 worked for all of 30 minutes or so
any idea how long its likely to run for on a fully charged battery? only need to run like this for a couple of days till i can get a replacement

brushes worn out or a huge build up of carbon dust causing problems......but probably brushes

Probably brushes. Instead of forking out for a new unit, why not buy some new brushes for it from Gold Lion Autoelectrics on eBay? They cost about 3-4 pounds.