Evening , I have a transit custom 2017 270. I’ve spent far too long trying to locate the washer fluid pump fuse. Going through the Ford website with the VIN and looking at fuse specification it doesn’t exist. Does anybody have any knowledge on where it could be? Thanks 

There is NO fuse for the washer pump.

It is directly controlled by the Body Control Module (BCM). Very possible that you are suffering with water ingress to the BCM which is common on a number of vehicles including some models of the Transit.

@unofix thanks for the speedy reply. That is definitely not the answer I was hoping for 🤣 to make it a little more confusing the washer pump has failed before and when taken to a mechanic came back working with them saying they'd changed the fuse! 🤷🏻‍♀️

1 hour ago, LPirk said:

taken to a mechanic came back working with them saying they'd changed the fuse!

Ah !! "Mechanic" speaks with forked tongue 🤣

You need an Auto Electrician.

Bit of a long shot -- you could try Fuse 6 (15 Amp) in the BCM passenger compartment fuse box.

Check the BCM connectors. Firstly disconnect the negative battery lead (yes I know that is a huge  pain with a transit). Once disconnected remove the connectors from the BCM and check for water ingress and/or signs of greenish corrosion. You should also use a multimeter and check the operation of the wiper stalk to see if the screen wash button is working.