No output voltage on wiper when using pot as voltage divider
A potentiometer works in the same way as a simple two resistor potential divider, so here on the left is the equivalent of the schematic on the right showing a potentiometer. The middle output being the wiper of the potentiometer. On the physical potentiometer itself the middle pin is usually the wiper but I would recommend that you check that with a data sheet for the potentiometer. 

I hope that this clears up the connections and just for extra knowledge here is a formula which will work to calculate the output voltage from the resistance of the two resistors either side of the output:

$$\mathrm{Voltage\space Out} = \mathrm{Voltage\space In} \times \left(\frac{R_2}{R_1+R_2}\right)$$







simulate this circuit &ndash; Schematic created using CircuitLab