Evening All,

My wipers were behaving erratically and generally being **** (not parking, sticking etc) so i have replaced the motor, cable and wheelboxes (thanks to Busters guide). The relay also went pop at some point, although the wipers were working all be it erratically, so i replaced that as well.

However - now I don't get anything, i have checked all the fuses - nothing melted - but i dont seem to actually be able to locate the fuse they are actually connected to (i think someone has butchered the electrics at some point). The green / white cable to the relay and switch have no power. If i run a separate lead from a good 12v, and splice into the green white, i get nothing. If I apply 12v to the connections in the plug that the stalk connects to, the wipers work in medum / fast speeds (i presume this is because they don't go though the relay). Slow and intermittent wipe don't do anything.

Anything else i can try to troubleshoot. I wondered if the new relay was bad, but I'm not so sure.

You should have going to the motor:
Green permanent feed
Black - Earth
Red/Light Green
Blue/Light Green
Brown/Light Green

The first job is to make sure that the Black is a good connection to the motor body and to earth, otherwise it will try to find an earth through backfeeding along the other wires.
No idea where you get the Green/White from as that should go from the stalk to the indicator repeaters, so they shouldn't work the wiper motor, although there is a White/Green which is the 'flick switch'
However, yours might be a non-standard or post 2007 model

Thanks, I figured it out, the wiring diagram for the 300tdi shows Green/White for the live, however, its actually just green. That's what confused me, I think at some point there has been melting or a small fire in the fuse box, and its been replaced - with cables spliced in to a replacement from I guess a later model - non of the fuses are where they should be and the colours are different. However for the wipers, there was an inline fuse in the dash that had blown, so i have re-routed to the fuse box to save pain later on. All works.

One thing to note is that new Lucas wiper motors appear to be setup for LHD models out of the box, so you need to move the trigger on the cogwheel inside the motor to the other set of holes, otherwise park position is at 12 o'clock.