AO Silver Member
Join Date: Mar 2003
Just general things to look for - not specifically the SW.
Firstly can you hear the pump working under the bonnet when selecting rear wash? If not suspect the pump motor.
If thats not the cause check there is no other water leak in the tailgate area as hose connectors can come unplugged if the nozzle is frozen.
Lastly there is probably a non-return valve that stops water from draining back when its not working. If that fails it takes some time to re-prime the whole length of pipe. Does the nozzle eventually work if you hold the wash control for more than say a minute? If so look to replace the non return valve.
'A business absolutely devoted to service will have only one worry about profits. They will be embarrassingly large.' - Henry Ford.