Type 150/400 Autopilot

[oceanharmony]

The autopilot controller is ST6002 connected to a Type 150/400 course computer that powers a 24volt Linear Drive (M81134). When the Autopilot is engaged the Clutch acitivates (the wheel locks in position) but the autopilot does not correct course. After a few minutes an error message "DRIVE STOPPED" appears. The rudder limits are all in order. I checked the voltage at the course computer. Supply voltage is 24 volts but the Drive Motor output voltage is zero. Therefore conclude that no power is being supplied to the Linear Drive. Is this a failure of the actual Course compuer or some other issue?
Appreciate help.
John

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum oceanharmony,

The problem reported is most likely rooted in within the autopilot course computer's circuitry. The problem may be further fault isolated by testing the autopilot drive unit. Should no fault be found with the drive unit as a result of testing and the vessel's batteries be fully charged, then the fault would be deemed to be rooted within the autopilot course computer. Unfortunately, should the problem be rooted in the autopilot course computer, then the autopilot course computer, control head, and fluxgate compass transducer would need to be replaced as Raymarine's Product Repair Center can no provide service for the Type 150/400 autopilot course computer and then fluxgate and autopilot control head are not compatible with the current generation autopilots (i.e. Evolution autopilots). If replacing the autopilot with an Evolution autopilot, then a T70161 EV-400 Sail or EV-400 Power would be used in conjunction with your system's Type II Linear Drive.