intermittent complete power loss

[pineislander]

Yesterday, while running my 2021 coastal explorer, I experienced complete power loss. F300 engine and all electronics abruptly shut down. After a moment of confusion, I hit the power button and restarted. Engine and electronics ran perfectly for the remainder of the day. This is the second time that this has happened.

All electrical connections look clean and tight. As this is an intermittent problem, I am not sure how to troubleshoot. Any advice would be greatly appreciated.

 

[family affair]

There is likely another electrical connection you have missed. Check all terminals under the helm especially the kill switch. Pull your engine cowl and look at all grounds and electrical connections. Check the fuse panel in the engine for anything that isn't seated 100%.
Electrical gremlins due to poor connections are a PIA. Electrical gremlins due to a failing part are a nightmare. Good luck.

 

[pineislander]

There is likely another electrical connection you have missed. Check all terminals under the helm especially the kill switch. Pull your engine cowl and look at all grounds and electrical connections. Check the fuse panel in the engine for anything that isn't seated 100%.
Electrical gremlins due to poor connections are a PIA. Electrical gremlins due to a failing part are a nightmare. Good luck.

 

[pineislander]

yes PIA.

I will keep looking. . . . but the boat is barely a year old and the connections (that I have checked) are clean and tight.

What are the chances that it is a bad battery selector switch or power button?

 

[wspitler]

Try changing your battery selections and that could isolate a problem if it’s a bad switch. I did have a bad battery switch on my other boat. However that switch was quite a bit older than yours.

 

[deepdesire]

Since you lost all electronics as well as power, check your power path from batteries to helm. Helm power is protected by breaker in battery compartment near selector switch. If this power is interupted it will kill your motor and electronics.

 

[pineislander]

thx for the suggestions. I will continue troubleshooting and report back . . . .

 

[wspitler]

Should be covered under warranty! Call GW, they may have seen this before! This could be dangerous, so I’d get their attention.

 

[Halfhitch]

yes PIA.

I will keep looking. . . . but the boat is barely a year old and the connections (that I have checked) are clean and tight.

What are the chances that it is a bad battery selector switch or power button?

I guess the new boats have something I am not familiar with. What is this "power button" you mentioned? A key switch is no longer used??

 

[Hookup1]

It's odd that the engine shuts down and you loose power to all the electronics at the same time. I assume you have two batteries. If your house battery is dead and your running your engine the engine could be suppling power to the electronics. If the engine should stop for some reason then you would loose everything.

The engine battery must be good because you started and re-started the engine. The engine alternator will supply charging power to your house battery. As above if house battery is dead the engine can keep the electronics up and running.

I can't explain why the engine shuts down. Engines can run without a battery once started. Loosing the starting battery while running should not shut things down. I would take a close look at your kill switch. Unclip it and clip it back in.

At the dock turns all your electronics on and disconnect the boat from shore power. Put a volt meter on the house battery and check voltage. Should be somewhere around 12.8 volts. Check starting battery. Should be around 12.8 volts. This is normal fully charged battery voltage. Start the motor up. Check house battery voltage. Should be around 13.1 volts. Check starting battery. Should be around 13.1 volts. This is normal voltage while engine is charging batteries. Turn the engine off and reconnect shore power. Turn charger on. Both batteries should be around 13.1 volts indicating the charger is working.

When the problem happens again (and it will) make sure you go slow and observe exactly what shut down. All electronics shut down? No power to anything like the horn, stereo or wipers? Try to turn them on. Kill switch intact? Will engine start right up? Electronics will come up next?

This will help troubleshoot the problem.

 

[wspitler]

I’m not sure a newer engine will run without a battery at least in the circuit. I know it might damage the charging system. Creating an open circuit may denergize the ECU, so a bad battery switch might, just might cause it, however improbable. I see this as a possible dangerous situation given a power loss at an inopportune time such as going through jetties, handling following seas, and currents etc. The other possibility is some short to ground that causes extremely high amperage draw and drops voltage below acceptable limits. My Garmin electronics has an event log that will tell you what happened and Yamaha computer may also have data on what happened. If the kill switch is the issue it will not kill anything except the engine and the electronics and house bus should remain powered.

 

[SkunkBoat]

First, I usually don't say this but ..its a new boat, call your dealer. Even just speaking with them over the phone can be better than a chain of posts here.

Second, I assume it is a standard battery config. One motor and two batteries on a 1/both/2/off switch. The House 12V is connected to the motor start wire so it runs on the same battery as the motor, which is dependent on the switch position.
Typically people alternate batteries each trip or "out & back" in order to keep both batteries charged. Some people run the switch on BOTH to charge both. That is a dumb idea...but thats another discussion.

When the HOUSE12v is configured in circuit with the motor, a temporary sudden drop in voltage from starting the motor can drop out the electronics. This is because they automatically shut OFF if the voltage drops below a lower limit (10 volts generally). Isolating the House on its own battery is a better config...but thats another discussion.

Yes, new motors(the bigger ones) can have problems running if they don't have a battery connected.

The battery switches can fail and also the connections can be bad but you can't see them without twisting the switch around. Its not easy...see "First"


So, questions
Which position was your switch? To troubleshoot use the other position.
What do you mean by "power button"? Do you mean the motor Start button or the Red 40A breaker?
When your electronics shut off did lights,horn, pumps still work before you pressed the "power button"?

The most important question to answer is "What caused the motor to shut off?"

What is your skill/experience level with boats, motors, electrical?

 

[SkunkBoat]

Since you lost all electronics as well as power, check your power path from batteries to helm. Helm power is protected by breaker in battery compartment near selector switch. If this power is interupted it will kill your motor and electronics.

The 40A red breaker and House12V should have no effect on the motor or its gauges. You can disconnect the House from the battery entirely and still operate the motor.
The motor gets its power thru the starter cable and sends 12v out to the controls and gauges thru its motor harness.
The motor however can effect the House 12v if they are using the same battery. Starting a motor draws a lot of current and that can temporarily drop the battery voltage (which is the House voltage)

 

[Fishtales]

Could there be an intermittent draw of power that is causing the voltage to droop? I've only seen this when I had weak batteries and lowered the anchor/windlass and the draw would cause everything to reset. Never saw it under power though. Just a thought.

 

[Hookup1]

Too much speculation. Start with the dealer. Unfortunately the dealers don't listen to the "stupid" customer. I've had this with car dealerships. Frequently I ask myself "Do I know more about the problem than the person I'm talking to?". The answer is usually YES! But start there and don't be afraid to question their answers. All the input you get here will help you do this.

 

[drbatts]

If everything went dead at the same time. I would first start by checking the all the grounds on the batteries.

 

[seasick]

If everything went dead at the same time. I would first start by checking the all the grounds on the batteries.

So would I.

Also, Skunkboat has the right response: What is the battery configuration and what switch selections did you choose?

 

[Doc Stressor]

I once had the same problem 40 miles offshore. The power and engine dropped out periodically all the way back in. The cause was a loose connection at the common ground stud on the transom.

BTW, big Yamahas will not run without a battery connection.

 

[seasick]

I should also mention two things about connections;
Even though a terminal or lug may be tight, the crimp of the terminal to the cable may be bad. So in addition to checking if the terminal is tight, yank on the cable to see if the crimp is tight. Battery cable crimps can be tricky to check since the shrink tubing can make a bad connection seem good.
Secondly, most often the connections on the battery switches are on the back of the switch. You may need to dismount the switch to check those rear connections.

 

[glacierbaze]

How many hours of runtime for these two occurrences to happen? Flat calm water, or choppy? Being a relatively new boat, it could be that someone doing the electrical install got distracted, took a break, got replaced by someone else, etc., and there was a gap in the process, leaving a loose connection.