New boat issue - what's your diagnosis?

This one may be hard to explain, but I'll do my best. Note - I am taking the boat to the dealership Monday morning, but I'm stumped and curious to see what the knowledge here can diagnose blindly!

Boat now has 12.6 hours. We did the normal break in (this is our second new boat). Somewhere between hours 5 and 6 while running around 3k RPM (guesstimate) the boat just "went dead" as if someone had turned the key off. All gauges went to zero. This lasted a second or so, then it picked back up where it left off as if nothing happened. It troubled me, but I made a note and kept going.

Somewhere between 7-9 hours this happened again. Same exact thing, but at different RPM and speed. This time it was around 10mph or so, as we were messing around with surf ballast.

Fast forward to today. First time we had a group with us (8 total). Somewhere between 10.5 and 11.5 hours it happened again, but this time it completely died and I had to restart with key. All oil pressure, temperature, and voltage was normal. Checked oil and fluids. Over the course of the next 1-2 hours it happened 3 or 4 more times. Each one was at various speeds, some while cruise was on, some while cruise was not engaged.

Now I am a bit ticked off, but also know that these things happen so I have no ill will toward the boat manufacturer or the dealership. Plus I know they will take care of it as my dealer is solid. I do have to admit that it probably was a bit embarrassing more than anything with a boat full of friends that I'm trying to show off my new boat to.

So does anyone have any thoughts? My gut tells me it's definitely electrical, otherwise all the gauges wouldn't die simultaneously. Could it be a bad battery connection, some wire arcing, etc? Don't know really where to start, and will definitely let the dealer handle it.

Definately sounds electrical

Sounds like either a bad ground or a loose connection. Goingto be hard to find since its an intermittent problem.

I'm going to take a stab at armchair mechanic and say check the safety lanard/kill switch connection, I had a similar issue with a new boat a few years back.

I would try to tighten the battery clamps first. New boat overlooking the obvious. It may not have been tightened at the factory. Just my first thought.

I would say start with the safety lanyards as well, then to the battery connections and grounds. I don't think whatever it is is a serious issue.

Start at the safety lanyard, then check the harness plug at the engine, then check the main block ground and the ECM ground. Gotta be there somewhere.
Remember to come back on and tell us what the dealer found.

What boat? Did i miss something?

Do you have multiple batteries routed through a perko type switch? I had this problem (although had to restart boat, not where the boat came back on its own) and we isolated the issue to the battery switch cutting out when in the "both" position. Replaced the switch.

No perko switches - single battery.

I'll check the connections for the lanyard and batteries, but aren't the batteries just for starting? Alternator does all the work after that, correct? So in theory wouldn't the boat still run if the battery cables are loose, just have trouble starting?

And with the lanyard, someone told me the boat would indeed die, but all the gauges would still be working as the key would still be in the "run" position. This seems accurate. They also suggested the problem may be with the main fuse panel. I'm going to check all these today, but I need to take it in for the first service anyway so might as well let the pros look at it.

To the poster that asked which boat - left it out intentionally. I know how this board can get and didn't want to start the boat wars.

I know on my boat (06 malibu vride) if the lanyard is not positioned correctly the gauges will go dead. If you pull the lanyard while the boat is running, the LCD screen briefly flashes a message like "ignition cut" or something like that (that's not what it says but I can't remember the exact text). But that's only for a split second. Prolly before you'd have time to say "WTF" and look at the dash, all of the gauges would be dead and the boat wouldn't be running.

http://www.wakeworld.com/forum/showthread.php?t=777952

Nice detective work.

So if it's a lanyard issue, then the gauges would go dead? That's good news I think. The more replies I get it seems this should be a quick fix of a loose cable or wire somewhere. Hopefully it's one that's found quickly.

I didn't want to mention this earlier as to not "steer" people in a certain direction, but after hearing the lanyard mentioned a few times I remembered that I did joggle it around after it did it one time, and to the best of my memory I don't think it happened again. So hopefully that's what it is, but I'm not sure how to verify that without taking it on the water again. I think I'm better off just taking it for the first service and telling them what happened and letting them handle it. I was just sort of stumped and knew I'd get some suggestions here - probably the right ones!

some safety lanyard has the 12v to the gauges wired

a boat that new should be under warranty

It is under warranty and they are taking care of it - I was just curious to see if anyone could figure it out.

safety lanyard i say

Is it throttle by wire? I have a brand new boat less then 12 hours and same thing happened to me. I dropped it off at dealer 2 hours ago. As of now they think it is Throttle Positioning Sensor of some sort. Will get more diagnostic work tomorrow.

I'm not sure what it is. I assume its TBW. Their initial thought was a relay, but they are looking at it now also. Once I get the diagnosis I'll report back.

I had almost identical symtoms with my Prostar last year and it ended up being a short in the fuel pump wire. It would randomly short out the fuel pump and kill the engine. It's an older boat ('01), but could be the same thing. I'm curious what they found

mine just did the same type of thing,would sputter,die then beep the alarms.$12 lanyard switch and back up and runnin.fire it up and tap the switch area,if it stumbles that must be it,gl