check your air filter, make sure you have enough air going through the indoor unit. Is the system maintaining temperature? Fossil fuel add-on kits can be tricky to wire, but if it's a wiring problem it doesn't sound like it's a serious one. Who's the manufacturer? If this is the first season it should still be under warranty. Your contractor SHOULD have the info.
It matters not how strait the gate,
How charged with punishments the scroll,
I am the master of my fate:
I am the captain of my soul.
-- William Ernest Henley