Did you prime the pump? THis is what needs to done first, which the hose disconnected from the
check valve, You can also take the
check valve apart to make sure no debri entered it. The checkvalve has a 16psi cracking pressure the pump cannot crack this with air in the line. You must prime the pump first then reconnect the hose to the
check valve. Did you apply the 12 volts to the pump with the controllers blue wire disconnect yet?
And did you get pump flow to verify everything was hooked up. Secondly did you reconnect the hose to the
check valve/nozzle assembly (won't work with the nozzle not connected for it to overcome the check valves pressure.
You should get a solid mist after doing this.