Either the spray head is plugged up or your check valve is stuck closed. Try the GEO method of water, dawn dishwahing liquid, and Calgon. Ride around with it in the tank.
Tony & Ruth........... FMCA#F416727
2016 London Aire 4519, Freightliner chassis, Cummins ISX, 2018 Jeep Wrangler Unlimited, Blue Ox Avail with AF1. TST 507 TPMS