ignition breaker issue

Benny17441 · May 20, 2015

Not much information. Are you having a problem with the cranking circuit or is the engine just cutting out at idle once it is running? Does the engine rely on an electric fuel pump and/or does it have a heating coil? I would say that not knowing which component might be tripping the breaker it would not be safe for you to go to a 40A breaker. When a diesel engine cuts out at idle it is usually a fuel issue. An electric fuel pump that looses power could explain it. A malfunctioning heating coil could also trip the breaker. Is the alternator working properly? It is also possible that your 25A breaker has weakened and it is being tripped by a normal load but unless you test the circuit and its components I would not use a larger breaker.

Maine Sail · May 20, 2015

Ed,

Use your clamp meter around the wire coming from the breaker. Let us know what you see for amps when doing all the things you mentioned. If that circuit is exceeding 25-30A we need to figure out of this is normal, and what devices are actually powered by the ignition circuit, or if something has been "tagged on" to that circuit that is pushing the limits.

The wire size will determine how many amp breaker is safe but this could also be a short that happens due to vibration at idle etc.....

Bill Roosa · May 20, 2015

Well with no heater, glowplugs, or electric fuel pump there is not much that an ignition CB would power except the alternator voltage regulator and engine gages and lamps. A voltage regulator is not going to be drawing 20 amps nor will the engine gages and amps.
I suspect there is a bare wire somewhere shorting out due to vibration. Check the wires from the CB to the pedestal where they cross the engine compartment.

Bill Roosa · May 20, 2015

2 amps sound right. Check for bare wires near the starter solenoid and along the solenoid control wire from pedestal to solenoid.

Benny17441 · May 20, 2015

No electric pump, no glow plugs and engine cranks and starts fine. In theory the engine should not cutoff at idle as fuel ignition is not dependent on electricity. The governor does not seem to have the ability to meet a load when engaging the propeller. Check for an electric fuel shutoff switch which could be faulty if the boat is equipped with electric engine shutoff. Your breaker tripping and the engine shutoff problem are due to different but interacting problems.

Ralph Johnstone · May 20, 2015

Ed, maybe take this down a notch.

As you've described your engine and CB, it should start with the "ignition circuit' in the OFF position. The starter motor does not normally run through a breaker and I would expect a draw greater than 100 A on initial starting. Run the engine through its paces and all other operations with the "ignition circuit" breaker open.

The only electrical connection I can see with the engine may be if you have an external regulator on the alternator and this depends on how it's wired. Other than that, I don't believe there is any electrical applied to your engine.

Please don't leave us hanging as this is one of the more interesting problems to come though here in quite some time. We anxiously await the next installment

Benny17441 · May 20, 2015

What do you call the start stop switch? is it the key switch for on and off? This switch just powers the gauges, the starter solenoid and the alternator, once the engine is running it is independent. You have a fuel cutoff solenoid in the engine room but never used it, how do you shut the engine off? Is it installed. Does your key switch in the off position activate the fuel cut off solenoid? Look into that as malfunctioning solenoid could be both tripping the fuse and killing the engine.

Ralph Johnstone · May 20, 2015

gettinthere said:
The breaker and the engine start/stop toggle switch are interconnected.

This start/stop toggle switch intrigues me. As you describe it, it sound like it is there in place of a key ignition switch. Can you confirm ?

I think we've confirmed that your "ignition breaker" is supplying power to your alarms. You don't need alarms to run the engine although it's not the greatest idea around but a short run won't hurt. Please confirm if the engine runs with the "ignition breaker" in the OFF position.

I tell you, fly me down to your boat in the Bahamas, feed, board, and entertain me, and I won't leave until I've repaired your problem. As you can imagine, it's still cold here in Canada.

Keep the info coming.

P.S. Benny's idea of the solenoid STOP is well worth looking into.

All U Get · May 21, 2015

I just got this from a friend cruising north. It may apply. Mine is tied to a smart regulator and fire extinguisher that won't let me run the engine without turning these breakers on.

I reset the regulator by pulling the four-pin connector off …. Letting it set for a minute…and re-installed.

Wham… everything came back perfectly…. Working

TOM from Balmar…said “you’re a cruiser right ? As the solar panels, and the wind-generators get more efficient, and pump more and more amps into the systems…. The older ARS-5’s don’t know what to do with the higher, and higher voltages seen now days…. “ He tells all the cruisers that call… to “put circuit breakers, or shut off switches in the external power devices…. Shut them off IF your using the motor…. NOT required…. Sailing or at anchor YES… moving under power…. Shut them DOWN… “

SO……………. That’s the first time we’ve ever gotten an “HIV” alarm… So I guess we’ll take his advice..

All U Get

woodster · May 21, 2015

one sure way to find out is disconnect the external power sources and see if the problem stops happening then you will know

Maine Sail · May 21, 2015

gettinthere said:
RC

Switch on, buzzer buzzing it draws about 2 amps. Starting the engine very briefly flashes 25 to 26 amps before settling back down to 2 amps

It doesnt quit on me at start up, but at idle, shifting in and out of gear. Until the third time this morning and then it popped right away.

I made the swap and it starts OK and the weak breaker is handling low house loads OK.

I can get to George Town in a few days where there is some parts availability.

We need to figure out which wire is drawing the 25-26A. Your starter solenoid should be 10A or less. Now that you know what the CB sees now we need to isolate each wire off that circuit and see what it is drawing. Regulator, solenoid etc. etc... Regulator should be a max of about 7A when full fielded but ideally would never be wired to the ignition circuit for the full regulator load just the brown / ignition wire goes to ignition, which is fractions of an amp......

Does your clamp meter have a "peak hold" function for DC amps?? How long will it stay on before putting itself to sleep...?

Stu Jackson · May 21, 2015

gettinthere said:
There is no key switch. There is a toggle switch and a plunger. Flip up the toggle switch and the alarms go off. Press the plunger and the engine starts. Flip down the toggle switch and the engine shuts off. All of this in conjunction with the breaker on the DC panel on.

"...and the alarms go off..."

Does this mean the sounds from the alarms start or stop?

English is funny this way, some people say that when their fire alarm, for example, goes OFF, it means it is making noise!

Also, what engine do you have?