I have a 1998 C Class. Yesterday the wiper stopped mid cycle (in a rainstorm at 70 mph!). The car has a single wiper fitted to the front. These wipers describe a strange arc as they as pushed upwards about 1/3 of the way into the cycle and then pulled down about 2/3s in.

The point at which the wiper stopped is exactely at the point where it is pushed out.

On stopping the car I was able to play with the wipers and reset them. On starting them again they stop at exactely the same spot - with a little push they go past this point but always stop at this point. Each time I can hear the motor straining until it some sort of safety cut out comes in.

The garage I took it to are not entirely sure what the problem is.

Any ideas?

Thanks