Good luck with getting any help from Bill, as he is apparently too busy filling orders for HRO and AES.
Make sure the CI-V address is set correctly in the radio. If you're not getting any power out of the TT to the antenna, it is probably the L298. If you have the tools, you can check to see if the logic inputs to the chip are switching, and if they are, and not output, then it is the chip.
Just for the record... The max rating for the chip is 3 amps, and it won't take that very long. A short will destroy the chip post haste. However, the most common cause is an inadequate motor lead choke. You might want to read this: http://www.k0bg.com/controllers.html