Port Engine Only Starts When Battery Partition Switched to SB

[HeideMarie]

Twin CAT 3208-Ts in my 1984 Egg Harbor

Almost exactly 1 year ago, I acquired and ran her from Old Saybrook to our new home in Boston Harbor.

After many improvements, I´m finally able to start taking her out regularly -- so in the last year, I´ve only ran her appx. 5 hours.

Being new, I made the mistake of forgetting to check the water/fuel filter and made ran her for about 1 hour with the port engine Racor almost entirely filled with water.

Since then, I´ve done a ton of maintenance and service myself --- including the following:

* Drained the water from Racors

* Changed the fuel filters

* Flushed/Primed the injectors

* Added new fuel with Biobore JF

* Flushed the coolant system and replaced with new coolant

* Changed the oil filters and oil

* Replaced the air filters

* Installed new 8D batteries

* Installed new starter solenoid (port engine)

* Cleaned and tested all connections

* Tested to make sure there´s power to the alternator, relay assembly and fuel solenoid.

* Adjusted alternator vee belt

* Replaced a fuse in the helm for the ignition

Nevertheless, I´m experiencing an issue that I can´t figure out.

SB engine - fires and starts right away

Port engine - When I turn the key, the helm does not show volts (despite volts present at all points on the engine) --- unless I switch the Battery Partition to SB --- then she will show volts and start right away.

If I let the switch go, the engine dies.

If I hold the switch appx. 5 minutes -- then let go, all is fine and Port engine continues to run.

I have a new fuel solenoid/injector (6N-9988) arriving tomorrow morning.

Any other ideas or suggestions?

I was hoping to make an appx. 90 NM trip on Friday.

I will do a sea trial tomorrow to test at and have been trying to get a mechanic in for the past 9 months -- there´s a chance one could show up finally tomorrow.

If anyone has a moment to watch / listen to short videos of them at various RPMs:

I´m not experienced enough to know if there´s any cause for concern.

Barring a failed sea trial, I´d like to run her long on Friday but would appreciate anyone´s feedback.

Many Thanks!

 

[DrissZougari]

Can you elaborate on your statement "unless I switch the Battery Partition to SB"!
Do you have separate battery switch for each engine?
I would suggest that you look into how all your batteries are configured in relation to the switches.

 

[Lepke]

On the solenoid of the non-starting engine: Take a wire between the small terminal and the terminal where the battery cable attaches. Or a piece of metal. and that will force the solenoid to engage. The red line in the image equals your starter circuit.
If it engages, the problem is in the key circuit and it will have to be painfully traced from the engine to the helm.

New batteries and draining the water was good, but most had nothing to do with the engine not starting. I suspect the Racors were not drained for a long, long time.

 

[HeideMarie]

Can you elaborate on your statement "unless I switch the Battery Partition to SB"!
Do you have separate battery switch for each engine?
I would suggest that you look into how all your batteries are configured in relation to the switches.

There are two 8D batteries which power the house and engines. One connects to port engine starter, the other connects to starboard.

Here's what's written in the manual:

"The two battery banks are wired with battery cable to a paralleling solenoid. This solenoid, when activtated by the battery parallel switch, will temporarily tie the two battery banks together for engine starting"

The way it's written makes it sound like the "battery par." switch is intended to be used every time you start an engine.

However, when tested, surveyed, sea trialed and in my minor use up to this point..... this switch was never used --- let alone holding it in for 5 minutes.

 

[HeideMarie]

On the solenoid of the non-starting engine: Take a wire between the small terminal and the terminal where the battery cable attaches. Or a piece of metal. and that will force the solenoid to engage. The red line in the image equals your starter circuit.
If it engages, the problem is in the key circuit and it will have to be painfully traced from the engine to the helm.

New batteries and draining the water was good, but most had nothing to do with the engine not starting. I suspect the Racors were not drained for a long, long time.

Thanks. I'll test this out.

I suspect you're likely correct -- the problem is probably the key circuit. I've made some progress on overall wire tracing in the vessel; indeed, it's non-frivolous.

 

[cafesport]

Was the replaced helm fuse for the port engine and did you disassemble the solenoid to see why it failed?

 

[Turtle Blues]

Port engine - When I turn the key, the helm does not show volts (despite volts present at all points on the engine) --- unless I switch the Battery Partition to SB --- then she will show volts and start right away.

Do you know which battery is supplying current at the engine before switching? Sounds like something is amiss in the primary connections.


If I let the switch go, the engine dies.
Safety switch current not present. A diesel doesn't care unless fuel is shutoff.

If I hold the switch appx. 5 minutes -- then let go, all is fine and Port engine continues to run.

This is enough time to partially charge a dead battery and allow the alternator to keep the system running.

 

[HeideMarie]

Was the replaced helm fuse for the port engine and did you disassemble the solenoid to see why it failed?

Yes and Yes

The AGC fuse at the helm did not appear blown, but replaced it anyways.

The port engine solenoid was corroded. Disassembled, brushed/polished it up removing the corrosion and reassembled checking for good connection/power. It worked/started normally 1-2 times --- then the same problem resurfaced (ie needing to switch the battery parallel on and hold it for 5 mins). So I replaced it for good measure.

 

[HeideMarie]

Port engine - When I turn the key, the helm does not show volts (despite volts present at all points on the engine) --- unless I switch the Battery Partition to SB --- then she will show volts and start right away.

Do you know which battery is supplying current at the engine before switching? Sounds like something is amiss in the primary connections.


If I let the switch go, the engine dies.
Safety switch current not present. A diesel doesn't care unless fuel is shutoff.

If I hold the switch appx. 5 minutes -- then let go, all is fine and Port engine continues to run.

This is enough time to partially charge a dead battery and allow the alternator to keep the system running.

Thanks. Those were my thoughts, but I just installed new batteries.

Do you think it could be the alternator?

 

[SoWhat]

Sounds like a fuel solenoid needs to warm up before it stays open. I would switch the solenoids and see if the problem follows the solenoid. The alternator simply charges the batteries. Shouldn't have anything to do with starting circuit. You might find an oil pressure switch that prevents the alternator from producing until a set pressure is reached.

I don't think you will be going 90 miles on Sat. NOAA is predicting 4-6' seas for MA Bay. Won't be a fun trip. Not something I would do with only 5 hours on the engines. Have a Plan B. Pickup up a mooring at Georges Is. and enjoy the weekend.

 

[HeideMarie]

Sounds like a fuel solenoid needs to warm up before it stays open. I would switch the solenoids and see if the problem follows the solenoid. The alternator simply charges the batteries. Shouldn't have anything to do with starting circuit. You might find an oil pressure switch that prevents the alternator from producing until a set pressure is reached.

I don't think you will be going 90 miles on Sat. NOAA is predicting 4-6' seas for MA Bay. Won't be a fun trip. Not something I would do with only 5 hours on the engines. Have a Plan B. Pickup up a mooring at Georges Is. and enjoy the weekend.

Thanks. New fuel solenoids are arriving today.

Good heads up on the weather --- we already planned on leaving early Friday (tomorrow) morning. NOAA says NE winds 5 to 10 kt. Seas 2 to 3 ft. That should be fine but always good to have backup plans.

Really appreciate the help thinking this through. I know enough to know how much I don't know - the collective wisdom here is awesome. Thank you, again.

 

[SoWhat]

NOAA forecast for MA Bay/Ipswich Bay a.o. 10AM today predicts NW winds at 5 knots, seas 4-5 on Sat, 4-6 Sun. Fri forecast is 2-3 but 3-5 by evening.Typical afternoon buildup. Beam seas so not most comfortable ride.

 

[DennisB1]

It seems like you are running on the port battery only. A new 8D battery is plenty of power by its self to start a 3208. The parallel switch would be use only if you had a discharge battery on nearly so to start an engine. It seems like you do not have power to the sb engine start switch unless you are connected to the opposite battery thru the interconnection switch. With the interconnect switch open do you have power to both engine starters? Use a VOM to verify the two heavy wires connect to the starter. If yes I would by pass the interconnect switch connecting both wires on the solenoid to one terminal. I believe with out being there that your engines will continue to run. Now you can take time to figure out why there is no power to the start switch and volt meters on the one engine. What is the voltage on each of the batteries engines off no shore power charging with VOM and then running. They should be about 12.7 engine off and rise into the high 13 or low 14 volt range with the engines running with a working alternators. I would go out if the alternators are not charging. Just some of my thoughts. Good lock

 

[Turtle Blues]

Post 10 has an interesting thought on failing solenoids needing warmup time to hold. Did replacement make a difference? Post 13 has a good map (which I actually draw) on starting voltage checks to determine issue. Just pulled an older engine harness today and changed all terminal ends to find an intermittent short and lower resistance in general. Voltage readings will immediately tell what's what with the alts. let us know when you find the culprit.

 

[TowLou]

Grounds ok? Sounds as a lose or corroded connection somewhere if holding it longer keeps it going.

 

[HeideMarie]

TowLou, TurtleBlues --- agreed -- I will be checking / reworking the ground.

I've recently discovered two other (non-engine) ground issues on the same battery bank.

 

[jgwinks]

Do your battery to starter cables have fuses? Most don't as it's not required, but some do. Mine do, and one popped. That engine then would only start with the battery combine switch engaged and being a mechanical diesel it would continue to run. Replaced the fuse and all's good but I probably will remove the fuses anyway, they're not necessary.