Not sure what is going on with the pin switch. I ended up not using mine because I have the pin switch for the rear door connected to the wiring for the pin switches in the other two doors so that my dome light comes on when the rear door is open. I think I posted this before, but for some reason, when the indicator light on the switch is lit it nullifies the switch. That way when one of my doors was open, the indicator light would come on because the dome light was on, and the switch wouldn't work to open the rear door.
Actually you connect post 87 of the four post relay to post 87a of the five post relay (per the diagram). That way the high voltage/wattage output from the four post relay connects into the second relay to power the popper.
I hope this makes sense, because when I read back through it, it sounds like complete bunk.