is there a windshield washer relay

Relays under hood in the 'Power Distribution Center' Most relays are the same type, meaning you can diagnose by swapping with a known good one like a heater fan or fog light relay.

There is no relay for that there is a fuse.

You can run a jump wire from postive battery post to wiper motor bottom wire low speed next one up is high speed. Known problem in distribution center weak circut board on wipers. Sole replacement if wiper motor and switch is good. Does other things on wiper switch work except wiper motor? Then check distribution center itself?