[CA] Keeping Autopilot in use without Raymarine MFD

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Evan,

Understand that unlike later Raymarine MFD designs, the SeaTalk communications interface of the E-Series Classic MFDs was designed to output power to the SeaTalk bus. However this feature was initially included within the system to address systems featuring a very small SeaTalk buse featuring the MFD and GPS sensor alone. In such systems, switching the MFD ON would also supply power to the SeaTalk bus. In systems featuring a larger SeaTalk bus, it was recommended that MFD SeaTalk/Alarm Cable's red lead not be connected to the SeaTalk bus to prevent an underpowered SeaTalk bus which would potentially cause the reported symptom.

For systems having a SeaTalk bus, Raymarine recommended a best installation practice of powering the autopilot's control head(s) alone via one of the autopilot course computer's SeaTalk ports. To do so, all 3 leads of the SeaTalk cable which has been interfaced to the autopilot control head will be used to interface the other end of this SeaTalk cable to one of the autopilot course computer's SeaTalk ports. For the SeaTalk cable connecting the system's other SeaTalk devices to the autopilot course computer, it was recommended that only the data (yellow) and ground (shield) leads of this cable be interfaced to the autopilot course computer's other SeaTalk port. The power lead (red) of this SeaTalk cable would then be connected to a dedicated switched 12V power circuit, permitting the circuit to be powered independent of the autopilot.

Should your autopilot be interfaced to the autopilot control head(s) in the manner specified above, then it is recommended that:
- the SeaTalk ports of the autopilot control head(s) be inspected for signs of corrosion
- the plugs of the SeaTalk cables be inspected for signs of corrosion and to ensure that they have been fully seated
- the leads of the SeaTalk cable connecting the autopilot course computer to the autopilot control head(s) are free of corrosion and have been firmly seated within the corresponding terminals of the autopilot course computer's SeaTalk port
- the vessel has been connected to shore power, its batteries have been permitted to obtain a full charge, and while still connected to shore power, the autopilot is tested again. Should the autopilot continue to report SeaTalk Failure, then it would be recommended that a SeaTalk cable which has been connected to a 12V power circuit alone be connected to the autopilot control head's second SeaTalk port.

Should the SeaTalk Failure persist thereafter, then it would indicate that a failure has occurred within the SeaTalk communications circuitry of either the autopilot's control head or within the autopilot course computer. As it is possible for one of the autopilot course computer's SeaTalk ports to fail (to include not supplying sufficient power) while its second SeaTalk port is fully operational, it would recommend that the autopilot control head's SeaTalk bus be shifted to the autopilot course computer's other SeaTalk port to correct the problem. Should this not resolve the problem, then it would be necessary to test the autopilot course computer with another compatible autopilot control head (ex. p70S, p70RS, etc.) to fault isolate the problem. Please note that Raymarine's Product Repair Centers can no longer service SmartPilot (S1G/S2G/S3G) autopilot course computers.