Problem with Coke Oven and unloader

[Bigpappa305]

Ok so I've basically created two rail loops one for the Coke Oven and one for the Blast Furnace that pretty much automate production of steel. My problem is that the unloader I have emptying the cart chest full of coal into the Coke Oven is filling the output slot not the input, so the Coke Oven won't work. I've tried putting the unloader on a different side as well as decreasing the amount that it puts into the oven, but it still keeps putting it into the output slot. anybody have any ideas?