Intermittent Fails to Turn Over on Start 150 Optimax

[MichaelJ3]

Prelim results:

Brand new starter installed. Same intermittent no crank, same symptoms, Bendix engages flywheel, won’t crank it about 25% of
time. Family member diligently tracing wires hoping to find a
loose connection...otherwise we are mystified.

[lpugh]

Did the starter come with a new solonoid attached
If you follow the steps in post 3 exactly, you will find your problem without guess work
Exact locations of test leads is imperative
Test the Battery first

[lpugh]

Report back with actual test reading for each of the steps
If you would like, you can call me at 916 813 0321 and will walk you thru this step by step
You will need a DVOM, fully charged and tested battery and 10 to 20 minutes of time
I will require the CCA and reserve minutes specs of your battery and actual CCA test results before beginning

[MichaelJ3]

Yes, starter came w/ integrated new solonoid. Merc P/N 892339T01

Specs on the battery are:

• Item Number: SLI31AGMDPM
• Brand: X2Power
• Voltage: 12
• Format: BCI Group 31M
• Lead Acid Type: Deep Cycle, Dual Purpose (Starting/Cycling), Starting
• Capacity: 100AH
• Cold Cranking Amps: 1150
• Reserve Capacity Minutes: 220
• Battery Type: Ultimate
• Capacity 20hr: 100AH
• Chemistry: Lead Acid
• Color: Blue Top
• Lead Acid Design: AGM
• Made in the USA: True
• Marine Cranking Amps: 1370
• Product Category: Marine/RV
• Product Sub Category: Starting Lighting And Ignition

We will get a load test on it...

[MichaelJ3]

Talked to Father in Law earlier, he gave up, took it to the local Merc Mechanic...will report when fixed what the issue is

[MichaelJ3]

Father-in-law picked up the boat today, supposedly fixed:
Battery was load tested at the dealer -- No Iusses, good battery.
Fix was a second solenoid in the circuit (not the one mounted to the Starter).
We were both unaware there is a second solenoid in the circuit...Don't have the P/N from Father-in-law, but he said the bill was an hour of labor, the part, which was $63, and tax...

Anybody know what is this second solenoid for?

He now has a spare starter on the shelf, in case it ever fails...

[lpugh]

It is called a slave solonoid, think of it as an amplifier for electrical current, it boosts the current available to the main starter solonoid and insures the voltage does not drop to low. Same as relay low current circuit to activate a higher current circuit

See test number 2 on post number 3

[MichaelJ3]

Figures...the one voltage I forgot to measure.

Oh well, father in law and I got educated, and that is always a bonus!

Sure would like to see a schematic of this circuit, but probably have to buy the service manual for that.

Generally, they must want a really low current to the ignition switch, and the current required for the main starter solenoid to close is probably a little larger 5-10A, so they staged the solenoids? First solenoid only takes a small current to close to close, closes a switch that can carry the current to energize the starter solenoid, which then closes the high current Starter Circuit? Makes sense, esp if as an engine manufacturer you aren't sure how long the ignition harness is going to be, who is going to make the switch, etc...leaves you options...


In in all seriousness, thanks for all your help!

[EuropeanAM]

Figures...the one voltage I forgot to measure.

Oh well, father in law and I got educated, and that is always a bonus!

Sure would like to see a schematic of this circuit, but probably have to buy the service manual for that.

Generally, they must want a really low current to the ignition switch, and the current required for the main starter solenoid to close is probably a little larger 5-10A, so they staged the solenoids? First solenoid only takes a small current to close to close, closes a switch that can carry the current to energize the starter solenoid, which then closes the high current Starter Circuit? Makes sense, esp if as an engine manufacturer you aren't sure how long the ignition harness is going to be, who is going to make the switch, etc...leaves you options...


In in all seriousness, thanks for all your help!

For the purposes of explanation, let's look at the circuit in "reverse".

No schematic required- think of it like liquid flowing through a hose. Positive battery terminal provides 12V+ to engine, and into engine harness. A Red wire from the engine to ignition switch provides 12V+ power, in the START position, power is bridged to the YELLOW w/RED STRIPE Circuit ("S" Terminal).

Current travels that circuit through the Neutral Safety Switch in the control, down the wiring harness and into the engine harness, activating the SLAVE solenoid. When the slave solenoid is activated, it's LARGER GAUGE Yellow w/Red stripe wire sends 12V+ to the Solenoid on the Starter, activating that solenoid, which bridges power to the starter motor itself.

12V+ power can easily travel over 55' in the average bassboat before it comes back to the engine in a "Start" circuit, which would result in an unacceptable Voltage Drop (thus, a "Slave" solenoid is used to cause a more direct, higher-amperage supply and consistently activate the STARTER solenoid).

[MichaelJ3]

Thanks Don, makes total sense! Appreciate you and Leon!

[SilverFox579]

Sure would like to see a schematic of this circuit, but probably have to buy the service manual for that.

Not that expensive and worth every penny IMHO. Contact Rhonda @ European Marine and she'll set you up.

[MichaelJ3]

Reviving old thread from last year. Why? Because There is still an intermittent no start on this engine we cannot figure out. Seems to happen more often after sitting for a week or so vs just overnight.

Very occasionally, the engine will not turn over. All battery terminals have been cleaned, order on battery is right, X2 Power Grp 31 AGM battery gets charged using DualPro/Pro Charging Systems DeltaVolt TriPro 15x3 charger always plugged in when not in use.

Symptom is starter engages the flywheel, just doesn’t seem like there is enough torque to spin it over. Seems to only happen on cold starts when boat has been sitting a few days; once engine is warmed up or used for the day, always starts.

I had the cowling off and Top Cover/airflow baffle off yesterday, and did observe that there seems to be a fair amount of play in the belt. The long run between the compressor and the alternator seems to have a lot of slack while running and the tensioner seems to have a fair amount of motion.

I asked my father in law if he had ever replaced the belt. Answer was no. Engine went in service in July of 2006, now at 462 hrs, it’s clearly due, and I told him that.

Any chance a stretched belt could affect amount of torque required to start? Seems far fetched.

But given the high quality battery, replacement of both the full starter (including solenoid) as well as the slave solenoid within the last 30 hrs of use, We are sort of at a loss for what this issue could be.

[MichaelJ3]

Here is a video of the latest fails

[lpugh]

Start from the beginning in Post #3
What are the specs on the battery in use
What are the battery test results CCA and state of charge
Post that info here and then we can proceed to step 2

[aussiejake]

Mine did the same, found the brushes in the starter motor were worn. I replaced them and all is good again.
But if your starter is new then that possibly rules out worn brushes.

[MichaelJ3]

Start from the beginning in Post #3
What are the specs on the battery in use
What are the battery test results CCA and state of charge
Post that info here and then we can proceed to step 2

Leon, Started at your debug steps on Post #3, and now am more confused than ever.

1) We don't own a load tester, so did not actually test the battery (which, I agree could be a contributor, but don't think that is it) The battery is the one listed in post #24 of this thread. On the couple days we tried this, the battery was fresh off an overnight plugin off a 3 bank, Dual Pro/Pro Charging Systems Professional Series 3x15A Charger. Even after about 15 good starts and 10 bad start attempts, the resting voltage on this battery was 12.86V. This is still an open item, but is not the prime suspect at this point.

2) Voltage measured on the starter cable between starter and starter mounted solenoid is 0V consistently on a failed attempt, and about 10.7-11V on a good start. Yet, on every failed start attempt, the Bendix clicks and engages the flywheel, and for a very brief moment tries to turn it.

3) Voltage from Battery Positive terminal to starter motor cable is about 0.9-1V on a good start, and a solid 12.86V on a failed attempt, which would tend to imply starter mounted solenoid not closed, but Bendix tried to engage and motor tried to turn over, see video above)

4) Voltage from GND to Battery negative terminal is 0V on failed attempts, could not get a good attempt to measure it on.

So, We still had the old starter from last year, with its starter mounted solenoid, and the new starter (<1 yr old), available.
We swapped the old for the new, and same symptoms as shown in the video recurred...so those symptoms and voltage measurements I gave above occur with two separate starters and 2 separate starter mounted solenoids.

Right now, I am thinking, since the battery and Slave Solenoid have also been replaced since this began happening, and it continues...the issue is either in the Slave Solenoid (although this is hard for me to swallow, since on every attempt, the bendix engages), or there is an issue in the main ground from the block to the battery.

I don't see how it could be the key switch, or slave solenoid, since the bendix engages on all start attempts.

Anyone know where the negative battery cable attaches in this motor? It wasn't obvious to me yesterday as we were wrenching.

[SilverFox579]

I asked my father in law if he had ever replaced the belt. Answer was no. Engine went in service in July of 2006, now at 462 hrs, it’s clearly due, and I told him that.

Any chance a stretched belt could affect amount of torque required to start? Seems far fetched.

NO. There is, however, a HIGH probability the stretched belt is affecting alternator efficiency. The belt is overdue for replacement, recommended service interval is every 4yrs.

Think I'd be testing engine cables at this point, certainly possible to have a corrosion inside the insulation. Does this boat have a battery switch? If yes, remove ALL cables and connect engine only cables direct to battery and report back.

Leon see post #24 for the X2 specs.

[MichaelJ3]

NO. There is, however, a HIGH probability the stretched belt is affecting alternator efficiency. The belt is overdue for replacement, recommended service interval is every 4yrs.

Think I'd be testing engine cables at this point, certainly possible to have a corrosion inside the insulation. Does this boat have a battery switch? If yes, remove ALL cables and connect engine only cables direct to battery and report back.

Leon see post #24 for the X2 specs.

Belt is on order, will be replaced. That said, Boat has onboard charger and charger had been connected all night, and these tests were first thing in AM, with charger (Pro Charging Systems/Dual Pro 15x3 Professional Series) Indicating solid green light on all three banks.

All the tests performed yesterday were with engine cables connected direct to battery, and no other cables connected.

[lpugh]

Leon, Started at your debug steps on Post #3, and now am more confused than ever.

1) We don't own a load tester, so did not actually test the battery (which, I agree could be a contributor, but don't think that is it) The battery is the one listed in post #24 of this thread. On the couple days we tried this, the battery was fresh off an overnight plugin off a 3 bank, Dual Pro/Pro Charging Systems Professional Series 3x15A Charger. Even after about 15 good starts and 10 bad start attempts, the resting voltage on this battery was 12.86V. This is still an open item, but is not the prime suspect at this point.

2) Voltage measured on the starter cable between starter and starter mounted solenoid is 0V consistently on a failed attempt, and about 10.7-11V on a good start. Yet, on every failed start attempt, the Bendix clicks and engages the flywheel, and for a very brief moment tries to turn it.

3) Voltage from Battery Positive terminal to starter motor cable is about 0.9-1V on a good start, and a solid 12.86V on a failed attempt, which would tend to imply starter mounted solenoid not closed, but Bendix tried to engage and motor tried to turn over, see video above)

4) Voltage from GND to Battery negative terminal is 0V on failed attempts, could not get a good attempt to measure it on.

So, We still had the old starter from last year, with its starter mounted solenoid, and the new starter (<1 yr old), available.
We swapped the old for the new, and same symptoms as shown in the video recurred...so those symptoms and voltage measurements I gave above occur with two separate starters and 2 separate starter mounted solenoids.

Right now, I am thinking, since the battery and Slave Solenoid have also been replaced since this began happening, and it continues...the issue is either in the Slave Solenoid (although this is hard for me to swallow, since on every attempt, the bendix engages), or there is an issue in the main ground from the block to the battery.

I don't see how it could be the key switch, or slave solenoid, since the bendix engages on all start attempts.

Anyone know where the negative battery cable attaches in this motor? It wasn't obvious to me yesterday as we were wrenching.

Check the voltage that the slave provides to the main solenoid
The starter solenoid has one circuit to shift bendix and another with a contact disc that passes current to the starter motor. If the voltage from the slave to the starter solonoid is about 10 volts or more, this would mean the starter solenoid is failing since there is no voltage to the post that feeds the starter motor
Sorry I overlooked the post 24. Do test the battery to be sure it is still good
I am just a little concerned of 1.0 voltage drop on the positive side, would feel better if it was .5 or less, would to like no know on the negative, Should be no more than 1.2 total

[MichaelJ3]

Want to check the main ground connection to the motor, can someone advise where it is? Can't seem to find where the big negative battery lead connects electrically to the block or a ground bus or whatever it hooks too...please advise.