Replaced the self-parking relay tonight, in the dark. when I had the dash cover off, I took the wiper motor assembly out, cleaned and re-greased the gearbox, and adjusted the float on the motor shaft so that it now has the tiniest bit (just enough so it turns freely). I also cleaned the earth tab and chassis, and the motor contacts.
So I was more than slightly irritated when, having reassembled all, the motor still needs a mechanical kick (waggle of the wiper arms) to get it going. It's good enough for tomorrow (unless there's a blizzard - unlikely in the Bristol area), but it does need sorting.
The stalk switch is less than a year old. It might be making a poor connection, being Britpart'n'all, but I doubt it. It's next on the list to check. I doubt it will sort it though.
So to the questions: is the motor so tired I'll have to replace it, or can I fettle the commutator/brushes with care? It's got two machine screws or bolts running the length into the gearbox casting, but I guess there must be variants. There's nothing obvious by way of access to the brushes, but it looks like the screws would let you take the backplate and end bearing off to gain access (assuming the commutator is at that end!). Anyone successfully stripped and rebuilt one?
Other thought: is it worth me taking the dash apart to lubricate the Bowden cable? The gearbox grease wasn't too solid (seen worse), but I'm sure the cable would benefit from WD40 then new grease, is that worth the hassle?
I suppose I can always drop the windscreen onto the bonnet for a while. Who needs warmth anyway...