Hi Brent......
....It's in my ADI II manual. You can go to TruTrak's website and download the manual. It's on page 16 in my manual, so you don't need the whole book.
Basically, you press menu, menu..select "setup" with the rocker. Press down arrow to ""serial data format"..press "enter" and a popup window will show the various settings. Use the keypad to select "NMEA IN/NMEA out"., press enter., select 4800 baud rate.Press menu to enter the advanced NMEA page. Select "advanced NMEA setup" and press enter. Use the arrow keypad and enter to select "Fast output" or turn off GPS status, waypoint route and Garmin proprietary".
This should correctly set up your 494 to provide RS 232 serial data to your TruTrak.
Regards,