If you don't know what the Repair Manifesto is, have a quick look here.
One of our windshield wiper arms stopped working correctly. Looking it up in the manual, it said that nuts sometimes had to be tightened. Cimmy didn't know where they would be. So, having a quick look at the wiper assembly myself, I saw there was a round-top nut where the arm pivoted that was a little loose. Simple! So today after a visit to my sister's, she borrowed a wrench and tightened it up. Sure enough, it worked fine afterwards 🙂