malcolm rees

I have a Citroen C5 Exclusive Saloon, Diesel, 2008. The front window wipers have an intermittent fault whereby they either don't work at all or get stuck mid-screen or in the upright position. We tried putting them in the upright position by pressing the wand within a minute of turning the engine off and this sometimes works but then they don't always work next time. Sometimes they move position when unlocking the car with electronic key. Currently the drivers side is struck in the upright position and the passenger side is stuck in the down position. Is there any fixes or reset for this fault?