No rear wiper - missing relay?

Hi my rear wiper doesn’t work I’ve WD40 the mechanism but nothing. Rear washer jet is fine.
It has a fuse (haven’t pulled it as was awkward to do so with the box in place, but noticed the far left relay is missing.
However when I check the wiring diagrams this doesn’t seem connected to rear wiper circuit. So I’m a bit confused. Also should that other relay but smaller and metallic, not black and plastic like the others?
Thanks