It sounds like you actually have a Dish 1000.2 (one LNBF with three "eyes")... each of those ports is capable of sending signal to 1 dual or single tuner receiver....
Just connect the line that goes to the receiver to any of the OUT ports (if you look directly at the ports, the 3 leftmost are the OUT ports, the 4th, rightmost is the IN port used to connect another Dish to that LNBFs internal switch, when needed)
That "splitter" is called a Seperator, for future reference.... the LNBF you have combines 2 satellite signals on one cable... the seperator splits those signals to the 2 satellite ports on the back of your receiver to power your dual tuners.
Once you do that, run a Check Switch, let the receiver Lock on a satellite and exit out of the Point Dish screen.... it will download new software, at which point you can call to activate the receiver.... wait 20-30 minutes or so and you should be good to go.
Edit: This is assuming you have the dish pointed correctly.
