Both of my 2002 Infiniti Q45 washer jets are spraying with very low pressure. The manual states that the jets have a check valve built into them, so I doubt they both got clogged at the same time.
What is the likely cause of this?
The check valves are there to prevent fluid from draining back to the tank so that the spray happens as soon as you ask for it. Weak output from both jets suggests a common point of failure. Some things to check:
Another possibility might be a build up of mineral deposits or other "gunk" in the nozzles – especially if you have hard water.
Or if you're someplace cold they could be frozen.
I had the same problem on my Subaru Forester, Opened the hood and found that the reservoir cap was off. Replaced it and it worked perfectly.