autopilot problem

[Frederick]

Auto pilot / water press pumpA little while ago my autopilot kicks off when the water pressure pump is started.I checked the electric circuits, voltage, put aluminum-foil around the pump, but problem persist.Does anyone ever have the same problem, ideas, solutions.

 

[Terry]

Hi Fred, we had a similar problem on our 1991...

P42. The AP would switch to standby whenever one or both of the reefers came on. The basic problem was low DC power. The original Heart 1800 was reaching the end of its life and as a result was failing to keep the batteries properly charged. I replaced it with a Freedom 25 from Xantrex and I now have loads of power. Check out store4power.com, which is where I purchased ours.Terry

 

[Allan Frey]

autopilot

To add some more data, I've seen an st4000+, while motoring, suddenly turn the wheel more than 180 degrees and the chart plotter boat symbol started to go backward. Batteries were fully charged so that wasn't the source of the problem in this case. Couldn't relate it to any event. AP and chart plotter were turned off and then back on and all worked fine.Allan

 

[Debra B]

voltage loss in the main circuit

You probably have a voltage loss somewhere in the main linkage from the battery to the breaker panel. A part of the circuit wired with undersized wire could do the trick - causing a voltage drop at higher amperages. If the voltage drops when a pump kicks on (this is a high amp load) then the auto-pilot will act like the power was shut off at the breaker.

 

[Frederick]

short circuit?

Thanks to you all, Debra, you put me on thinking, I checked if other high-load systems do kick off my autopilot too, but until now only the water-pump is kicking-off the A/P. The voltage drop on the start of the water-pump is significant; looks like internal on start-up the water-pump creates something like a short circuit.Does that sound possible?