Had my Z sit for the winter months, started it up today to clean it up and take it out however the power steering isn't working. There is fluid in the resevoir, any idea on what else it could it before going the route of a pump replacement.

 

Is the belt ok? Is the pump spinning? If it is, check the plug on the steering rack. Maybe an animal chewed trough the wires. If that pressure sensor on the rack isn't working, the steering goes full stiff.

 

That^