Starting Woes

[Wotname]

Originally Posted by Greg Shakeshaft

……..

I do possess a multimeter but it is only a cheapish one and I am wondering whether I should be investing in a "fluke" or similar in order to give myself the best chance of finding this (and future) faults.
………..

When I return from the boat later today, I will certainly be updating everyone on my progress.

Regards, Greg

A cheapish one will work almost as well as a Fluke or similar. The Fluke will last much longer and for precision measurements will be more accurate but you don't need accuracy for this work.

The only complaint I have about cheap digital multimeters is the response time, typically they can be a half a second or more. When I am used to almost instantaneous result from a Fluke, that half a second seems like ages to wait for a response

And oh, the cheap leads sometimes fail faster than the expensive leads

Good luck but I reckon that now you are armed with all this info, the intermittent fault won't manifest itself. Something these electrical problems often throw in the towel when they know you are getting serious about finding them

[DeepFrz]

I hope the first thing you do is to check for corrosion in the connector A/B. If you have contact cleaner it would come in handy here.

Do not short the yellow wire to ground as it is a hot lead +VE.

Wotname, D is the stop switch and E is for the Glow plugs.

[Wotname]

Originally Posted by DeepFrz

I hope the first thing you do is to check for corrosion in the connector A/B. If you have contact cleaner it would come in handy here.

Do not short the yellow wire to ground as it is a hot lead +VE.

Wotname, D is the stop switch and E is for the Glow plugs.

Yep, finally worked it out with OP's help and the realisation this morning that the numbers of the wiring at the connector A/B were the pin numbers, not just the colour coding. The brain couldn't seem to see that last night .

Agree totally with your other comments

[undercutter]

Originally Posted by Greg Shakeshaft

The only strange anomaly is that the engine has never ever failed to start when leaving the marina, it only ever happens when I attempt to return.

Herein may be the clue. Although the problem could in fact be loose or corroded connections or wires it sounds tome like a battery problem. The fact that there is never a problem at the marina when the batteries are fully charged or on a charger but after having sailed for a time using I assume the same batteries all of all sudden there is a problem. Not sure how old the batteries are but this would be the first place to start. A simple load test on the batteries would help. Has this been done?

[Wotname]

Originally Posted by undercutter

Herein may be the clue. Although the problem could in fact be loose or corroded connections or wires it sounds tome like a battery problem. The fact that there is never a problem at the marina when the batteries are fully charged or on a charger but after having sailed for a time using I assume the same batteries all of all sudden there is a problem. Not sure how old the batteries are but this would be the first place to start. A simple load test on the batteries would help. Has this been done?

There is certainly some good logic in this reasoning even if it contradicted by the reports that the solenoid doesn't even engage when the fault manifests itself and then finally when it comes good, the engines fires OK. Sort of suggests the battery might be good.

Still easy enough to check although the corroded connector A/B also must be a very likely suspect. 22 years is a long time in a small boat!

Don't you love intermittent faults!!!

[Sardean]

No worries Wotname, lets hope Greg has some success

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[Greg Shakeshaft]

Hello again everyone and thank you all for your continuing assistance and support.

Well, I spent the best part of the afternoon aboard my boat with the sun beating down on my bald spot as I crouched at the bottom of the companionway slowly and meticulously working my way backwards from the starter motor.

I took off each cable and cleaned up the terminal connections as best as I could and ensured that as I replaced them, a good contact was made.



I also attempted to measure if indeed a voltage drop was occurring along the yellow cable "4" as previously referred in other posts. However, I could not get a reading from the multimeter when I attached the black (coms) lead to the terminal at the solenoid end of the yellow cable and the red lead (volts) to the +ive side of the battery. I have to admit at being a little confused when reading the instructions already given by forum contributors and I apologise if I have misunderstood the instructions.

I also double checked that the batteries were holding a charge and measured the voltage across their terminals



I am wondering if there are other components which need to be considered as potential problem areas. I stumbled upon a relay and what looks like a circuit breaker which both look a little out of place and whilst I cannot see any mention of them in the wiring diagram, they both look like original equipment and are wired into the loom.

I attach a photo of them.


I will be returning to the boat tomorrow to continue my checks. I may venture out onto the ocean as it only ever seems to play up when I head home.

Kind regards, Greg

[Sardean]

Finding an intermittent fault is a lways difficult,
next time the fault occurs unplug the yellow wire with blue lug. With another peice of wire Momentarily connect from that spade terminal on starter motor to the big plus terminal , this bypasses the starting circuit, if this works then a problem exists in starting circuit.

another way to check for wiring fault in starter circuit is to connect a light bulb or spot light (20 - 100 watts) from negative on battery to the yellow wire off the starter motor, this should glow bright when you press the starter button.
Next get someone to hold in start button, or better join wires together on starter button, then jiggle and bump all your wiring a bit at a time if you have a loose/ faulty connection anywhere the light will dull or flicker.

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[exMaggieDrum]

Hi Greg,

I understand how confusing this can be. Start circuits can be complicated.

I just looked quickly through the above posts and suggest that you also double check the "ground" (DC negative) cable and connection to your motor. If you have already done it all good but it is often a cause of intermittent starter problems (and alternator problems). If that cable and connection are not sound then a weak current will be available to the starter. I can't tell you where this cable is connected to the motor. Sometime it is to the base flange of the starter. But it will be a big cable and should be at least the same size of the starter positive cable (the big one to the solenoid). Take it off, clean it, and reconnect it - tight. Like you did the others. I have found them loose before and I should have suggested it previously. My favorite adage is "check the ground first" and I didn't say it here.

The first pic of the C channel bracket shows a little "baby" solenoid. It is normally not part of a starter circuit but I have seen them in circuits before. It might also be part of the glow plug circuit if you have glow plugs. It can NOT carry enough current to run the starter but it can allow a small current to provide stronger current to the solenoid on/off that is on the starter itself. That can help with voltage drop issues from the key switch to the solenoid. You'll have to trace the wires to figure out what it is for. But it will have 4 (or 5) contacts on the bottom side. The wire going to the one labeled "30" is the main power lead that is switched on or off by the little solenoid (same as for the bigger starter solenoid). The output of the solenoid is on contact "85".

So it goes to the item that is being turned on or off by the little solenoid. Contacts "86 and "87" are the control wires. One will be a ground and the other will be control wire. E.g. if it controls the glow plugs (which need a strong current) then the "85" will go to the glow plugs. "30" will go to a battery positive source (like to the starter positive).

One of the other wires will go to the ignition panel for the glow plugs. I am only giving this as an example because it may not be what you have.

But beware that some little solenoids like this can be NO - normally open, or, NC - normally closed. They can also be used to stop motors that have an electric stop solenoid - a lever that shuts off the fuel to the motor. I doubt your little motor has one, but if you do, then that part has to work as well for the motor to run but it wouldn't prevent the motor from turning over if it didn't work.

Re: voltage drop - I would do every thing else before trying to measure this. It is confusing. And it can only be measured when current is flowing through a wire. There will always be some voltage drop through any wire.

But you made a comment which I may have misunderstood. It sounded like you did not get 12 (or 13) volts measured from the big positive cable to a good ground. A "good" ground is what you need. So I would go to the battery negative if your lead will reach and the other lead to the big positive on the solenoid. The start battery switch should be ON. You should get full battery voltage on that connection. If you don't then the circuit is bad either from the battery to the battery switch or to from the battery switch to the starter solenoid. Then check the voltage from the positive on the solenoid to the motor (some bare and clean metal) but not to the big negative cable I mentioned above. If you have good voltage (same as measured at the battery then your main battery power to the solenoid/starter is "probably" good.

BUT - you can see full voltage even with a bad connection or wire as voltage can be measured off a weak connection or a small wire. And a weak connection will not allow enough current to flow to start. (A voltage drop test can show this but you can only see it when you try to start the motor and the solenoid clicks but the starter doesn't turn over. You can only measure it while you have the start button or key switch set to start. When you release the switch, as you would when you get the motor started, you no longer have big current flowing to the starter and you won't see a voltage drop. You will always see some voltage drop as it is caused routinely in a start circuit. But it can be large if a connection is bad.

You would measure it from the battery ground (on the battery) to the big positive post on the solenoid. A buddy helps do this unless you have a remote starter switch or have long enough arms to reach the starter switch and watch the meter at the same time. I always carry a couple of extra leads with my meter with alligator clips on both ends to extend the reach of my meter leads.

You said the solenoid and starter checked out so it is in the ignition/starter circuit or in the big battery cables (positive and ground).

I hope this may shed some additional light on the matter. But I'd double check the battery ground/negative to the engine first. After that it is a question of finding good voltage at each part of the ignition circuit - power to the ignition panel, power out of the starter switch, power to the starter solenoid "on" wire (what makes the solenoid click). I draw pictures/diagrams myself as it disciplines me to draw a complete circuit and shows sometimes a part I missed. And you will certainly understand that part of your boat really well after that. And put the diagram in your boat docs. You may need it again. Good luck. You'll get it done.

[Sardean]

Hi Greg,
I agree with exmaggiedrum, great advice, another quick way to check battery capacity is to pull the engine stop lever or solenoid so motor doesnt start then crank engine for 10 seconds if it does this without slowing down then batteries are ok. Note if motor does slow down it will be due to bad connection (will be hot) or bad battery. As mentioned by others voltage at battery should not drop below 10v

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[Wotname]

Originally Posted by Greg Shakeshaft

Hello again everyone and thank you all for your continuing assistance and support……….

I am wondering if there are other components which need to be considered as potential problem areas. I stumbled upon a relay and what looks like a circuit breaker which both look a little out of place and whilst I cannot see any mention of them in the wiring diagram, they both look like original equipment and are wired into the loom.
………..

I will be returning to the boat tomorrow to continue my checks. I may venture out onto the ocean as it only ever seems to play up when I head home.

Kind regards, Greg

OK, you are getting a lot of good information but perhaps you are also getting information overload.

Let me try to be succinct for once

For the moment, forget the multimeter as others have suggested. You don't need it at this stage and we can return to it later. And it will only help at the times when the fault is evident. There is plenty to do even when the fault isn't evident.

First go though the checklist below.

Clean +ve battery terminal on battery, battery switch and starter motor.
Clean -ve battery terminal on battery and engine chassis.
Inspect and clean 12 pin connector A (both sides)
Inspect and clean 12 pin connector B (both sides)

Now confirm as best you can that the circuit is as I have described earlier. This information is taken directly from the circuit you provided BUT who knows what modifications a previous owner might have made and not recorded.

From previous post:
So the start solenoid engage circuit should be:

+ve from battery
battery switch (Q) on
circuit breaker (Z)
pin 1 on connector (B)
pin 1 on mating connector (A)
start switch (F) normally open contact (RHS)
pin 4 on connector (A)
pin 4 on mating connector (B)
start solenoid on starter motor ( R ) small terminal (yellow wire)
though the solenoid coil
-ve though chassis
battery -ve.

Find each component in the list and look carefully at it. See if the wire colours are the same and that there is no obvious extra wires. If it seism to be accurate, then this is good as you now know where the fault must lie. It has to be in that circuit.

The next bit is important.

Intermittent faults can be diagnosed by inspection, replacement or traditional "trouble shooting" i.e. meters and stuff.

Now is the time for some more replacement especially if the fault only presents itself while sailing. Traditional trouble shooting is not pleasant while underway or if you really need the engine to start.

So to replacement.

Make up a temporary starting switch and have it really to install in a jiffy. This is just a length of wire with a blue spade terminal on one end, any old switch in the middle and a alligator clip or similar at the other end. You might or might not want to add an inline fuse (say 5 amp) near the alligator clip end - your choice. I wouldn't bother but others are more careful than me

When the fault next occurs, remove the existing yellow wire on the start solenoid, fit the temporary wire in it's place and attach the alligator clip to battery +ve terminal. Operate the switch and motor should turn over.

If so, the fault is somewhere in the parts that has been bypassed. If it doesn't turn over, the fault remains in the battery, heavy battery cables, starter motor or the solenoid itself.

[Greg Shakeshaft]

Hello again everyone,

Firstly, can I thank you all once again for your continuing, help, support and assistance that you are giving me in trying to resolve my intermittent engine starting problems. I think it would be fair of me to say that this is true testament of the camaraderie that exists between sailors and yachtsmen down the ages.

Unfortunately, I prior engagement crewing aboard a Beneteau First 35' prevented me from returning to my boat today and continuing my efforts towards resolving my reoccuring problem. However, I will be going back again tomorrow, armed with renewed enthusiasm to try and find the fault once and for all.

In particular, I will be constructing a backup starter system which bypasses all my existing wiring etc so that should my fault return at that crucial time, I will have some means of starting the engine and returning safely to port.

Once again, I want to thank each and every one of you for all the excellent advice and ideas that you have given me. I will no doubt be keeping you up to speed with my progress in the days and possibly weeks ahead.

Kind regards

Greg

[Badsanta]

I still suggest you have your battery tested. I went through simular problems. The volts tested great but battery had NO capacity.

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[Sardean]

Originally Posted by Badsanta

I still suggest you have your battery tested. I went through simular problems. The volts tested great but battery had NO capacity.

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You would normally still hear solenoid make clicking noise with low battery

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[DeepFrz]

Some of the connections in the pictures posted don't look great to me. The connection of the White wire coming off the Cct. breaker feeds +ve to the three switches on the panel. It looks like it could use cleaning up.

Do the glow plugs or the stop solenoid ever refuse to work at times? If so it could point to that cct. breaker and its connections. Also sometimes just resetting the cct. breaker could clean its internal contacts.