When using multiple servos to control a surface that usually only uses one (such as two servos for elevators), the two servos are connected into different slots then "mixed", where one slot is used to control the other as well by making a setting in the transmitter. See this site for a list of Frequently asked questions for the 9c, that should have answers to what slot to use, what settings to make, etc. Your manual, although not the easiest to use ( I have a 9c too) does give answers to many of your questions.

See airplane programming #9, #27 and #40.

Don't despair. It will all work out and you will have much greater control (read finer) that if you use a "y" cable to connect two servos.


http://www.futaba-rc.com/faq/faq-9c.html


P.S. Your lead from the switch (bringing power from the battery) can be plugged into any empty "slot".