Dead in the water

So we warm up the boat, pull away and about 10 minutes later we get a low voltage alarm on the engine instrument panel. Voltage meter showed <10v.

We are at low RPM so I increase speed and the alarm goes away and the voltage comes up.

About 30 seconds later voltage drops, alarm sounds, engine sputters and dies. Dropped anchor and called Tow Boat US and they are estimating a 5 hour response time. So, I might as well be useful and try to trouble shoot the problem.

We still have DC to the instruments, meters show 12.9 volts. Measured voltage at starter and it is 12.98. Installed a new fuse recently in the house bank but it is still good.

There is a fuse in a small red wire off the alternator positive post and it is good. But there does not seem to be continuity between alternator positive and negative posts should there be?

When we turn the engine key on there is nothing.

Suggestions?

Thanks,

Gene

Check the connections, particularly the grounds at the battery bank and the main battery switches.

Do you have Nigel Calder's book; Boat Owners Mechanical and Electrical Manual?

Has a really good troubleshooting section.

That's all the help I can offer!

XSBank - since we have electrical to instruments and other DC circuits but a dead engine panel would the problem most likely be in the engine 12 volt side of things?

We have dedicated engine starting battery and separate house bank.

Thanks for the reply,

Gene

What engine? If it’s an energize to run stop solenoid, then low voltage could keep it from staying open. Have you measured voltage at the control panel where it is complaining? Perhaps measure the voltage at the stop solenoid with the key switch on to see what it measures.

If low voltage is preventing the stop solenoid from assuming the run position, you might be able to hold it in place and see if the engine starts. If it does, then secure it in the run position with a zip tie or other and you might be able to get home.

Mechanical or electric engine control system??

Cummins 6BTA.

Battery connections are clean and good at the start battery.

I will have to check the engine manual about the solenoid.

Twisted Tree -

Solenoid does not pull in when we turn the key to start and push the start button. I held it in place manually and still no luck. Disconnected the wiring harness and checked voltage with key on - none. Checked again with key on and pushing start button, again no voltage.

Thanks,

Gene

SlowsailNC said:

Twisted Tree -

Solenoid does not pull in when we turn the key to start and push the start button. I held it in place manually and still no luck. Disconnected the wiring harness and checked voltage with key on - none. Checked again with key on and pushing start button, again no voltage.

Thanks,

Gene

Click to expand...

Do you know for certain that it is energize to start, and not energize to stop? I don't know, but someone like Ski will, so hopefully he will see this.


Do you have a stop button to shut down, or do you just turn off the key switch? If there is a stop button, that might energize the solenoid if it's energize to stop.


But all indications are that you have no power to the engine controls, including the solenoid, and probably the lift pump too. Since it failed gradually, it's probably a bad connection somewhere that has become corroded over time. If you have a manual with wiring diagrams that will be you best guidance, or someone who knows that engine in detail.

On a 370 you can zip tie the fuel solenoid in up position, then jump the starter at its solenoid on the other side of the engine. To stop, cut the zip tie. Hopefully your throttle and shift controls are cable and not electronic.

Sounds like you have some sort of fault in the wiring going from engine up to helm and back down to engine. One lead on fuel solenoid should power up with ign on, the other lead enegizes with starter for pull in coil, third is ground.

Ski in NC said:

On a 370 you can zip tie the fuel solenoid in up position, then jump the starter at its solenoid on the other side of the engine. To stop, cut the zip tie. Hopefully your throttle and shift controls are cable and not electronic.

Sounds like you have some sort of fault in the wiring going from engine up to helm and back down to helm. One lead on fuel solenoid should power up with ign on, the other lead enegizes with starter for pull in coil, third is ground.

Click to expand...

Is there an electric lift pump? He held the solenoid and it still didn't start, so maybe no fuel because of no lift pump?

Ski -

Shift/Throttle cables are manual.

I can zip the fuel solenoid in the up position but not sure about jumping the starter solenoid. That is just low current, correct?

Thanks,

Gene

twistedtree said:

Is there an electric lift pump? He held the solenoid and it still didn't start, so maybe no fuel because of no lift pump?

Click to expand...

Fuel is not the issue - there is no power to the engine panel. I am thinking that a fault in the wiring harness between the engine and the panel is most likely the problem.

Unfortunately I don't I will find that before Tow Boat US gets here (although their ETA is 4 hours from now).

Thanks to all for the suggestions, keep them coming if you have any ideas.

Gene

If no voltage from b+ side on alt to the battery bank you use with the battery switch in the right position check from batts on + side going back to alt. Batts, batt, switch, then alt if no voltage there could be a inline fuse from the alt. You will need to inspect the wires and be sure the connections are clean. Heck the motor may of even lost a ground. Check the b+ side to the motor with a volt meter should have system voltage there as well.

On the starter is the big red cable (batt positive) and a smaller wire/terminal (both on the back of the starter solenoid) that fires the solenoid coil. You briefly jump the two together to fire the starter. Maybe 20 amps. Dont try to jump the two big lugs together, that would be too many amps for a screwdriver.

Bonus if you have a test lead with two alligator clips on it, that makes it easier.

Fuel lift pump is mechanical on these, no worries there.

if you're only 15 minutes away from the Marina, can you go back there with the dink and ask someone for a tow.....or raise the dockmaster on the radio to ask around ?

Ski in NC said:

On the starter is the big red cable (batt positive) and a smaller wire/terminal (both on the back of the starter solenoid) that fires the solenoid coil. You briefly jump the two together to fire the starter. Maybe 20 amps. Dont try to jump the two big lugs together, that would be too many amps for a screwdriver.

Bonus if you have a test lead with two alligator clips on it, that makes it easier.

Fuel lift pump is mechanical on these, no worries there.

Click to expand...

Ski - I am seeing two small terminals on the solenoid and the one large with the positive cable. One of the small terminals has a wire that goes to the starter housing, the other is a small wire - not sure where it goes yet.

Which of the terminals am I jumping? I do have a test lead with alligator clips, once jumped do I remove the test lead?

As I always tell my wife - Thanks For Your Patience!

Gene

Should be three terminals on solenoid: 1. Big red batt cable. 2. Pigtail that goes into starter motor case. 3. Smaller terminal with lead that disappears into engine wire harness.

Jump 1 and 3. Once started, take jumper off.

Exact position of the stuff varies with the brand of the starter, but all have the same basics.

That is exactly what I am seeing.

Then to stop the engine just cut the zip tie on the fuel solenoid, correct?

Thanks,

Gene

Yep, cut the zip tie to stop.

You have to love TF...

Thank-you Ski - worked like a charm and we are back safely in the slip.

If I can impose on you one more time. Since there was NO power to the engine instrument panel is there one thing that you would look at first in the wiring between the engine and the panel?

Also thanks to everyone who replied - all suggestions were welcome.

Gene

That was impressive! Hat's off to you, Ski.

Well done Ski !! Way to save the day !!

Somewhere around back of cylinder head I think there is a red button circuit breaker, check that is not popped. Otherwise, need to walk through the circuit point to point with volt meter, starting at starter lug and going up to helm. All boats are wired different, so no real solid advice. Do look for loose connections, especially grounds.

Could be something with the air preheater, but that should not have caused this issue.

Ski - understood, and if you are ever in New Bern the libations are on me!

Gene

Gene...please post your findings when issue solved. Thx, PD

TF should give out HERO badges.

JohnEasley said:

That was impressive! Hat's off to you, Ski.

Click to expand...

I agree. I think TF should create a special member category for individuals like Ski. Instead of “Guru”, I think “Hero” would be appropriate.

Everybody should have a Ski aboard, let start the cloning process

L