Hi Clive, on your post you say you have blown into the pressure switch and it clicks.Have you blown the other way down the pressure tube?
It is connected down below into a pressure chamber,this is usually the part that blocks up with old soap etc and then the air cannot get up the tube to the pressure switch.You will more than likely find this part blocked.Clear it out,re assemble and you have a good chance of curing it.ps Some parts of the wash are timed fill so it ignores the pressure switch.All the best.
Foxy
August 2008