Raymarine p70r reports low voltage

[crosswire]

Recently, I have started receiving frequent low voltage alarms on the Raymarine p70r control head. The controller is connected to a SPX 30 Smart Pilot using Sea Talk ng. The system has worked very well for about one and half years.

The boat's batteries are at 13.5 volts, and all the wiring connections are tight. The controller continues to work properly, even with the alarm message on the p70r screen.



Are either the controller or the Smart Pilot equipped with batteries that Raymarine does not mention in their paperwork? Or is there a way to adjust the voltage at which the alarm occurs?

[Hooked]

I had a similar problem with my Raymarine AP but when the alarm went off, the AP would not work. In my case, it was the breaker at the control panel. It was older and occasionally would not allow full voltage through to the AP.
YMMV.
Good luck.

[smac999]

The stng bus is droping voltage.

Is it powered via the pilot? Or inserted? Some of the ray pilots can provide power to the bus.

Measure at that point. Then measure at the end where the screen is. You can add another tee and drop cable then cut cable to measure wires

[crosswire]

Thanks, I will check the circuit breaker: however, it is only 40 years old. TIC.

The stng is powered by the pilot. The cable route goes from the pilot to a terminal block that integrates NMEA 2000 with the stng. From there the cable goes directly to the p70. The total cable distance is about 6 feet. Since my first post, I have dismantled and cleaned all the cable connections on the pilot, the terminal strip, and the p70. I have not had time to get the boat out to test the system with the cleaned connections; hpefully, this weekend.

The NMEA 2000 network has its own power supply. As the two networks are linked at the terminal strip, I did try using the system with only the pilot powering both networks; the low voltage alarms continued.

[crosswire]

Moving along....
Cleaning the connections did not stop the low voltage alarms. However, the DST800 tri-sensor on the network has lost temp completely and depth is inconsistent. I have been told that these data problems could be caused by water intrusion into the sensor head. This water may be causing a short that is affecting the network voltage.

[crosswire]

Working on what smac999 suggested, I may have found the problem. Although the SPX30 is receiving 13.4 volts for the boat's batteries, the voltage supplied to the ST and STng networks by the SPX is only 11.0 volts. I removed the 3 amp fuses powering the networks in the SPX and left the secondary power supply, direct from the boat's batteries, active. The networks now report 13.2 volts. I will see if this helps.

Does anyone know of a way to adjust the output from the SPX?

[jamhass]

I have had any number of problems with fuses/fuse-holders having high resistance due to corrosion. Replace the fuses and clean the holder contacts.