Lexus SC headlight washer issue

I had something similar happen on my old BMW 5 series. The headlight and windshield washer systems often share a pump or at least a common electrical connection. Could be a faulty pump or a relay issue. Are you getting any kind of motor sound when you try to activate either system?

I'm not hearing any motor sounds at all when I try to use either system. Is it possible that a defective relay would cause both systems to fail simultaneously?

Yes, it's definitely possible. A single relay often controls power to both systems. Given you hear no motor, I'd suspect a bad relay, a severed ground connection, or the pump itself has failed. I’d visit a workshop to have this checked properly.

Okay, thanks! Turns out it was indeed the cable connection of the pump, it was defective. Cost me 165€ to repair. Thanks!