A few things don't make sense here.
First, the "output" of a zener diode is usually the voltage accross it, but in your case that is also the supply voltage.
Second, the purpose of a zener diode is usually to create a fixed voltage from a higher voltage, perhaps unknown or varying. The zener acts like a shunt regulator, meaning it draws the necessary current to drop the voltage to the rated value. However, that requires the voltage source driving the zener to have high some finite impedence. You are connecting the zener to a power supply. A ideal power supply has zero impedance by definition.
Show your actual circuit. That might make some of these issues more obvious, and will give is a basis for discussing it further.
