Jaguar S-type (2000) wiper mechanism sometimes very weak

Question

Recently, and not all the time, the wiper arms on my car are so weak that they get stuck on the last wipe of a screen wash 'job'. At first I thought it was friction with the window, but I've since tested by holding the wipers away from the window with my hands while the arms try to move it. I can feel with my arms holding the wipers that the wiper's arms are struggling to move the whole thing.

Inexplicably - other times they're fine.

I don't quite know whether it's purely mechanical, or relies on the battery, or involves rubber pulleys. Before I reluctantly take it to a repair garage (where they might quote for an expensive complete system replacement) I thought I might ask here to see if there is any knowledge of how these work in my model of car.

Answer 1

I had the same problem with my 2006 Jaguar S-Type. It turned out to be the bolt that attached the wiper arm to the chassis was very loose.

Answer 2

Double wiper blades are sometimes the issue.

Answer 3

I wouldn't recommend this solution generally, but I'm providing it here as it's what fixed it for me.

I sprayed liberal amounts of WD-40 into the area of the mechanism, and eventually the wipers started to move freely. They've been fine ever since.

I realize this is a seemingly obvious solution, but I did try WD-40 initially and it didn't work. It was only after spraying loads of it in frustration (some time later) that the wipers started to move freely.