My front & rear washers don't work or my rear wipers

I have a funny feeling the stalk is at fault for this particular problem...

Changed stalk still nothing

Did you get a new one or a used one from a breaker?

Perhaps check the fuse/relay box near the battery for poor connections.

I am certain the usual cause of this problem is the stalk as they have thin copper contacts that can wear/break.

Some suggestions that might give a few clues:-
As above, check continuity of stalk.
Check stalk has power.
Connect wipers directly to power, bypass stalk.