If you get a noise from the pump when operating the switch then the fuse is ok. The pumps are mounted under the washer bottle, when I have checked pumps I take drivers side front wheel off and remove front part of plastic wheel arch liner, the pumps are easy to replace because electric supply is on a plug and tube will pull off.
Some people use the technique of putting a tube (or just your mouth, but not such a good idea with all the gunge on the back of your car) over the nozzle and blowing air back down to try to dislodge any blockage, this may have limited success on rear washer because there should be a non-return valve in the pipe, if this valve is stuck open it will allow washer fluid to drain back to bottle and it can take a while for fluid to get back to nozzle when you operate washer, if it is stuck closed it will stop fluid anyway. The non-return valve should be accessible along top edge of tailgate when you lift tailgate fully you will see a tube running to washer nozzle, valve is an inline plastic whatnot.
While you are doing this I would replace headlight bulb.