Actually, you don't need a meter - you need a way to monitor the MIDI messages.
Drop the strip back on top, fire up the MIDI controller and only hit the pad at the top.
Then only hit the pad at the bottom.
Then hit both together.
Make notes of the messages being sent and adjust based upon that.
In short, if you don't get a message when you hit 'just' the top or bottom then you need to hit both at the same time.
At that point you would need a meter or scope to determine the signals being passed and if you could tie them together or if you need a double pole switch.