Garmin X96 Wiring
This will be serial as well. You'll need the cable from Garmin to connect this.
Garmin Blue to HS34 male pin # 2 (or #1 in dual serial config)
Garmin Yellow to HS34 male pin # 15 (or #14 in dual serial config)
The X96 frequency data will pass through the HS34 to an SL-30/SL-40 if you have those as well.