wiring up a solenoid valve

[jinmared]

Where would be the best point in my tractor wiring to get 12vdc to power a solenoid valve using a joy stick controller of some sort?
Thanks

 

[RPW]

Does the power need to be full time or only when the ignition is on?

 

[kenstrac]

The feed to the solenoid should go through a relay that is fused and goes to the battery, the joystick control should come from key switch with a fuse and feed the coil on the relay.