Raymarine instruments flash and low battery warning?

[monte]

Hi,
Sailing today my raymarine instruments started flashing on and off, and freezing occasionally. Then the E90W rebooted and then said..low battery warning. My batteries were at 85% 12.5V so I dont know why it sent that message. I found when I turned off the autopilot the system worked as per normal, but as soon as I turned it back on the problem returned. Screen flashing etc.
Thanks if anyone knows where to start looking would be great.
Monte

[noelex 77]

The most likely problem is there is a poor connection or possibly wiring that is too thin somewhere. The former problem is more likely given this is a new problem, but sometimes its a combination. The voltage drop of this sort of problem is dependent on the current carried. When the autopilot is turned off the current and therefore the voltage drop is reduced.

The battery voltage at the battery may be 12.5, but at the instruments it's dropping well below this.

[twistedtree]

An auto pilot can draw a lot of current depending on it's size. I agree that some combination of bad connections and/or undersized wire is the culprit. You will need to go in and measure the voltage at the instruments and AP and trace out where the drop is occurring.

[monte]

same thing happening today....notice a slight buzzzzz from somwhere behind the chartplotter. All fine till I engage autopilot then it craps out. buzz indicates bad connection there?

[noelex 77]

Normally 12v is not enough voltage to causing arcing/buzzing from a bad connection.
It may be relay chattering or buzzer going off inside the chartplotter due to the low voltage, but the voltage loss my be a long way from here.
With a multimeter you can detect where the voltage loss is occurring. If you don't know how to do this remaking / cleaning all the connections is very likely to solve the problem.
Sometime even with lowish currents the defective conection will get hot after it has been on so feel all the connections with your fingers.

[southace]

Originally Posted by monte

Hi,
Sailing today my raymarine instruments started flashing on and off, and freezing occasionally. Then the E90W rebooted and then said..low battery warning. My batteries were at 85% 12.5V so I dont know why it sent that message. I found when I turned off the autopilot the system worked as per normal, but as soon as I turned it back on the problem returned. Screen flashing etc.
Thanks if anyone knows where to start looking would be great.
Monte

My raymarine does the same! I have to switch to standby and re-engage it it's painful fault!

[noelex 77]

Originally Posted by southace

My raymarine does the same! I have to switch to standby and re-engage it it's painful fault!

It may be an unrelated problem, but the Raymarine chartplotters are very sensitive to low voltages. It's worth checking the voltage at the chartplotter when it's on.

A good clue is if the problem happens when the battery voltage is low, or other equipment is turned on (such as the autopilot as in the OP case) then its very likely low voltage is the cause. If its a random problem it's more likely it's a different fault, such as a software glitch.

Another diagnostic test is to turn the screen brightness down very low. This reduces the power draw and voltage drop in the wiring/ connections. If the problem stops it suggests a voltage related problem.

These tests are not foolproof, but are useful indicators

[twistedtree]

Originally Posted by monte

same thing happening today....notice a slight buzzzzz from somwhere behind the chartplotter. All fine till I engage autopilot then it craps out. buzz indicates bad connection there?

Bad connection, almost for certain. You should deal with it quickly to eliminate any fire risk.

[Pete7]

Originally Posted by noelex 77

It may be an unrelated problem, but the Raymarine chartplotters are very sensitive to low voltages. It's worth checking the voltage at the chartplotter when it's on.

Monte, note how thick the wiring is that Raymarine supplies. There is a reason for that. Might be worth checking that any other wiring it is joined to is also up to the job.

Pete

[roverhi]

A bad ground connection will cause low voltage. Would suspect the ground for the autopilot motor as a good place to start. Remove the connector, clean it up and reinstall. Might want to do that with all the other connectors even if the A/P ground cures the problem. Corrosion just sneaks into everything that requires electrons on a boat.

[monte]

Thanks guys, had a raymarine tech check it out today. Took 3 hrs for 2 guys but they found the problem. The 30A autopilot fuse had a loose screw on the connection terminal so the supply was intermitent. It does still buzz a bit when its turned on but he seemed to think all do that. Im not convinced but will test it over the coming weeks.
Thanks again for the help !