Try fuse first - cheapest option. If not that, I suggest the pump's goosed. Someone may have a trick to try to get it going again first, before you start haunting scrap yards.
Pull the plug off the pump on on the washer bottle, put a 12v bulb across the plug contacts, get an assistant to operate washer, bulb lights? you have power all the way to pump, so you probably need new pump. If bulb dosen't light then you have to check connections all the way back.
There will be a fuse relating to it in the fuse box which you need to check but if fuse has gone then there will be a reason, probably because pump has failed.
Boum Boum, there is your answer, but sometimes it may pay to get the bottle off and rinse it out with some very hot water, ie with time whatever you put in washer bottle it sort of becomes slightly brittle ie like( dregs) and as above it could stop the pump working, or it might blow the fuse if the pump is trying to push the water up the pipe but it can't because of the obstruction. Or it could well be the nozzles blocked
Use tester to check you have power going through to pump. If you have then get a new pump, might be about £20. Not familiar with yours but usally an easy replacement, just pulls out of washer bottle.
You don't say what make of camper it is but I would suggest that if you can hear a buzzing when you operate the switch the pump is working. One thing to check for is that there is often a gause on the inlet to the pump which becomes blocked.
Screenwash can often turn to gel and cause low / no flow.
------------- Love a lot. Trust a few. But ALWAYS paddle your own canoe!!
Minds are like parachutes:- They only function when they are open!!!
Those who talk don't know.
Those who know don't talk.
I have a problem with my windscreen washer suddenly not squirting water on to the windows, there was three holes in the pipe with teeth marks. So far I have caught 6 mice in the engine compartment, hopefully that is the lot. I went to a cats home for the loan of a cat to stick in the engine compartment, but they were not that keen on the idea.
With all this wet weather mice are being flooded out of there usaul habitats, fields and hedgerows, and what could be more better than a nice warm engine.
Chap down the road had his fuel pipe gnawed, started his engine amd had diesel all over the engine.
So if your windscreen washers stop working check for mice.