i50 Tridata replacing ST70 SeaTalk Raydata

[MissGuided]

Good evening, I purchased a i50 Tridata to replace a 1998 Raydata ST70. I also bought a D244 Seatalk 3-way adapter to get power. Although the new (i50 boxed instrument only) no longer comes with a Seatalk to Seatalk ng cable, my marine store provided me with one. Installed i50 in dash with D244 adapter to connect my Seatalk Ray Autopilot to power i50 unit up. No problem, powered up and my 1998 depth transducer showed depth. Problem with speed and temp transducer.... connected as decribed in 4.4 Transducer connections and 3 dashes blank speed and blank after sea temp but depth works perfectly. Anything I missed? is the speed and depth transducer compatible? Not sure on speed / temp ducer model number... boat is a 1998 SeaRay 370 Sundancer, I'm the original owner. Everything worked until intermittent failure of the ST70 display last year followed by a blank screen mid season this year. Thanks in advance for your help.