ST290 GPS and NMEA issues

[smorast]

Ah, apologies- I did not write that very clearly at all. What I meant to say was I will remove the red seatalk wire (+12V) from the ST1 input to the course computer, leaving the bare and data ST1 lines intact. This will leave the other larger gauge power input as the source of power. Will leaving the ground (bare) wire connected create a potential ground loop?

As to the DPU. Do I remove the red and bare wires of the ST1 line currently connected to power input of the DPU and insert them into the ST1 input of the DPU? Will the DPU operate without power/ground input on those lines?

V/R,
smorast