RD 33 connection to smart depth sensor



I have a RD 33 display which is working fine with the GP-32 connected to the NMEA0813 port and power fed into the centre (male) can bus port. There are no other connections to the display. I have just installed an Airmar smart depth sensor but have had no luck connecting it. Some advice would be appreciated.

I have also tried connecting the sensor plug into the top of a T connector and then along a backbone cable to the RD33 which is directly connected to the top of T connector into the centre port. The power is connected into the other end of the T connector. This allows the display and GPS function to work but still no depth. Am getting 13volts between the red and black wire on the Can Bus backbone and 1.39 volts between the Can H (white) and Can L (blue) wires to the depth sensor. I am thinking the problem might be that I am not using any terminator caps for the free ends of the T connectors ( none were supplied with my T connector /backbone cable kit) Are the terminators essential?
I connect the sensor directly into the spare female can bus port the sensor starts beeping but no depth or temp data at the display. Should I be able to directly connect to this port or do I need to connect it via a Can Bus back bone cable and the T connectors into the centre port?

Any advice would be most appreciated.
Regards Mike
Did you wire the sensor similar as described here http://www.furunousa.com/ProductDocumen ... nd%20alone).pdf

The sensor is already mounted, facing to the ground while ship is in the water?

When you pull the sensor out of the housing you should here a ticking noise.

Sometimes NMEA works without Terminators, somtimes not. It is always a good idea to do it "after" the book and use the Terminoators
Terminators on each end of an N2K backbone is really not optional.