alternator/battery/winter woes

[do-drift-1]

i have a 325i e30 and my prob is i think my alternator's on its way out, was wondering as my mate offered a 318i alternator, will it work on the 325i, or is it more than likely that the difference in engines would mean it doesnt fit/or work, anywho the prob is this my battery drains the car cuts out and i end up stranded, so something not quite right, anywho my assumtion is the alternator, cheers in advance for any advice, Regards Richard

[Brianmoooore]

The most likely thing to be wrong with your alternator (if there's anything wrong) is the carbon brushes in the regulator pack. Just swap this over by undoing the two small screws that hold it in place on the rear of the alternator. No need to remove the alternator - just the air filter assembly for access.

[do-drift-1]

soo what do i do with the carbon brushes?, do i need to buy new carbon brushes or am i being a numpty here and misreading sorry :S

[Brianmoooore]

The carbon brushes are part of the regulator pack. Once you have removed it, you will see the spring loaded brushes at the back of it, and if this is the problem, one of them will be extremely short and show signs of arcing on its working end.
Simply pulling on the offending brush and stretching the copper braid that retains it slightly will bring the assembly back to life for a month or so.
As a long term cure you will need to find a second hand pack with brushes of a decent length, or you can invest in a new one.