Tue May 29, 2007 10:14 pm
biggest problem is water getting past the seal on the wiper arm shaft, and rusting in the tube it runs through, causing the wiper shaft to seize up. water also gets into the electric motor and the case of the electric motor can rust as well the rear of the case is black plastic and can be removed carefully or you will break the plastic tabs and it will never go back on correctly and allow water to get in. the grease needs removing and replacing the wiper shaft can be put gently in a vice to avoid crushing the tube and cleaned up a good way is to put a drill bit down it after the rust is removed,grease it up thoroughly,then fit it back together taking care not to lose the small plastic gear wheels (and they are small)....should of mentioned this first as when you open the case they are likely to fall out
the nearside motor is the control one. as if the nearside one stops it will stop the offside one from working. if neither work try that one first ....the shaft seals are available from bmw still as are the washer jets which can get blocked
if you can run a wire to each motor to see if they move, if they do i would still strip and grease them as ther will be at least 15 years muck in them if each one does work then try the large black relay in the fuse box(intensive wash one has 2 extra pins in case its been swapped for a normal one)and the relay on the side of the washer bottles (£80 from bmw or £5-£25 on ebay)swap it for another (this is where your mate comes in)borrow his one
i have a step by step account from a mag some where ill try and dig it up