ITC-5 Transducer led status

[kechikan]

Hello,
I have an ITC-5 connected to a I70s and a depth transducer P319 which was originally connected to a ST60+ depth display.
I removed the ST60+ and connected the transducer to the ITC-5, the transducer status led on the ITC-5 keeps blinking like nothing is connected to the depth terminal.
The boat is out of the water so I can't see any depth reading on the I70s, only tree dashes.
When I touch the face of the transducer, under the boat I can feel it is working.
Should the transducer light on the ITC-5 become steady when the boat is on the water?
Is there any way to find out if everything is connected and running as it should, before putting the boat on the water?

Thank you