Starter motor

[twinpot]

Good Afternoon.

I have a twinpot Lister with electric start,it is wired up as follows.

Large cable from battery to single red key master switch,large cable from master switch to starter motor,and a push button to start the engine.

My questions are,when i turn on the master switch, but don,t try to start the engine,would this draw some power from the battery,(does the starter energize or something),also once ive started the engine can i turn of the master switch,as this is only used to power the starter motor.

Thanks.

Twinpot.

[WotEver]

My questions are,when i turn on the master switch, but don,t try to start the engine,would this draw some power from the battery,(does the starter energize or something),also once ive started the engine can i turn of the master switch,as this is only used to power the starter motor.

No. Yes.

 

Tony

[RLWP]

Good Afternoon.

I have a twinpot Lister with electric start,it is wired up as follows.

Large cable from battery to single red key master switch,large cable from master switch to starter motor,and a push button to start the engine.

My questions are,when i turn on the master switch, but don,t try to start the engine,would this draw some power from the battery,(does the starter energize or something),also once ive started the engine can i turn of the master switch,as this is only used to power the starter motor.

Thanks.

Twinpot.

 

When you push the push button it turns on a solenoid which contains a switch that turns on the starter motor. All the rest of the time there is no current flowing through the starter motor or solenoid.

 

You may be able to turn the master switch off, but do check that the alternator isn't charging the starter battery through that cable. On most boats it will be. Ours does

 

Richard

 

No. Yes.

 

Tony

 

No. No*.

 

Richard

 

*battery charging

[DHutch]

*battery charging

Also fuel stop soleniod, oil presure sensor, anything else depending on the engine and install.

 

The system of using the +ve starter motor termial as a junction for all wires is a very common one. Cars/boats/pumps/gensets have been doing it for decades.

 

 

Daniel

[Sir Nibble]

Turn on, start engine, cruise. Moor up, stop engine, turn off. All bases covered, correct procedure, no worries.

[WotEver]

No. No*.

 

Richard

 

*battery charging

Ahh, well... I took OP at his word you see

[Chris-B]

Good Afternoon.

I have a twinpot Lister with electric start,it is wired up as follows.

Large cable from battery to single red key master switch,large cable from master switch to starter motor,and a push button to start the engine.

My questions are,when i turn on the master switch, but don,t try to start the engine,would this draw some power from the battery,(does the starter energize or something),also once ive started the engine can i turn of the master switch,as this is only used to power the starter motor.

Thanks.

Twinpot.

 

My question is .... WHY ?

[twinpot]

My question is .... WHY ?

Because i fitted a new starter battery yesterday and was taking readings with my volt meter,every thing was fine till i turned on the master switch to the starter motor,the volt meter was slowly droping volts on the starter battery,both battery banks are earthed to the back of the starter motor.The engine started fine and both banks were charging correctly,i thought that if i turned the master switch of after i had started the engine,whatever fault i had would only be there for a few seconds while i started the engine.on the back of the starter motor there is a screw on cap with a spring inside, the cap is missing, the spring is still there but is loose in the hole,can you tell me what the cap and spring do please,i think this has been missing for sometime.to make things a bit clearer charging is by a 1 2 both off switch,one wire from alternator to switch,1 wire from 1 to starter battery,1 wire from 2 to domestics,hope this all makes sense im confusing myself now.

[ditchcrawler]

Because i fitted a new starter battery yesterday and was taking readings with my volt meter,every thing was fine till i turned on the master switch to the starter motor,the volt meter was slowly droping volts on the starter battery,both battery banks are earthed to the back of the starter motor.The engine started fine and both banks were charging correctly,i thought that if i turned the master switch of after i had started the engine,whatever fault i had would only be there for a few seconds while i started the engine.on the back of the starter motor there is a screw on cap with a spring inside, the cap is missing, the spring is still there but is loose in the hole,can you tell me what the cap and spring do please,i think this has been missing for sometime.to make things a bit clearer charging is by a 1 2 both off switch,one wire from alternator to switch,1 wire from 1 to starter battery,1 wire from 2 to domestics,hope this all makes sense im confusing myself now.

Bite the bullet and find your fault, if not you will never recharge your starter battery, turn the switch the wrong way and blow the alternator, and if you have got an electrical fault may start a fire. I can't be bothered with what else could happen.

[twinpot]

Bite the bullet and find your fault, if not you will never recharge your starter battery, turn the switch the wrong way and blow the alternator, and if you have got an electrical fault may start a fire. I can't be bothered with what else could happen.

Why would i never recharge the starter battery, its on a completly different circuit.?

Why would turning the switch of blow the alternator,its on a complety different circuit.?

I know i need to find the fault,but all i really asked was do i actually need to leave this switch on after i have started the engine.

And does anyone know what the fault might be,as far as i can see it can only be the starter motor,but it works perfect.

Regards.

Twinpot.

[ditchcrawler]

Why would i never recharge the starter battery, its on a completly different circuit.?

Why would turning the switch of blow the alternator,its on a complety different circuit.?

I know i need to find the fault,but all i really asked was do i actually need to leave this switch on after i have started the engine.

And does anyone know what the fault might be,as far as i can see it can only be the starter motor,but it works perfect.

Regards.

Twinpot.

Because if you isolate the battery you wont be able to get any charge into it.

If it is a separate system with its own alternator then isolating it with the engine running will take the load off the alternator.

If you have a fault drawing enough current that you can see the battery voltage dropping then if it gets any worse it could get hot enough to cause a fire.

Sorry I can't help with the fault, you say only the starter motor is connected, if thats the case how does the battery get recharged? Could the fault be on this part of the circuit?

[twinpot]

Because if you isolate the battery you wont be able to get any charge into it.

If it is a separate system with its own alternator then isolating it with the engine running will take the load off the alternator.

If you have a fault drawing enough current that you can see the battery voltage dropping then if it gets any worse it could get hot enough to cause a fire.

Sorry I can't help with the fault, you say only the starter motor is connected, if thats the case how does the battery get recharged? Could the fault be on this part of the circuit?

If you read post 8 again that explains how the batteries get charged,i cant understand it either,the starter motor stays stone cold.

Thanks.

Twinpot.

[blodger]

If you read post 8 again that explains how the batteries get charged,i cant understand it either,the starter motor stays stone cold.

Thanks.

Twinpot.

When you say lister twinpot I am presuming air cooled and no gloplug/heaters as a starting aid. If there are any of the latter they use a fair few amps and cause a related voltage drop. It sounds as though the starter isolation switch has something else on it, as an ignition circuit, perhaps a duff relay for something although it sounds as though you have attempted to trace the circuits and found nothing. Starter should not draw any current unless and until the solenoid is activated to start it.

 

I wonder if the volts on starter battery were falling because it was commoned with domestic batteries (which were much lower)by the 1/2/both switch at the time you were measuring and it was incidental nor causal that you 'switched on' the starter motor circuit?

Edited March 4, 2010 by blodger

[twinpot]

When you say lister twinpot I am presuming air cooled and no gloplug/heaters as a starting aid. If there are any of the latter they use a fair few amps and cause a related voltage drop. It sounds as though the starter isolation switch has something else on it, as an ignition circuit, perhaps a duff relay for something although it sounds as though you have attempted to trace the circuits and found nothing. Starter should not draw any current unless and until the solenoid is activated to start it.

Yes you presume right,The live wire goes straight to the starter motor,with the switch in line,then you press a button to start it.as far as i can see that is all that circuit does.

Thanks.

Twinpot.

[ditchcrawler]

If you read post 8 again that explains how the batteries get charged,i cant understand it either,the starter motor stays stone cold.

Thanks.

Twinpot.

OK in post 8 you said "The engine started fine and both banks were charging correctly," where was the charge coming from to get to the starter battery?

[twinpot]

OK in post 8 you said "The engine started fine and both banks were charging correctly," where was the charge coming from to get to the starter battery?

If you read all of post 8 it will tell you.

Thanks.

Twinpot.

[RLWP]

<snip>

charging is by a 1 2 both off switch,

 

one wire from alternator to switch,

 

1 wire from 1 to starter battery,

 

1 wire from 2 to domestics,

 

hope this all makes sense im confusing myself now.

 

I've taken the liberty of reposting your post 8 and spacing it out to understand what you have said.

 

So there are separate wires dedicated only to charging the batteries.

 

Richard

[Sir Nibble]

This is interesting. Screw on cap with a spring inside? The only starter that leaps to mind is the CAV CA45 which seems a bit of overkill for a 2 cyl Lister. If that is the case, it really needs that cap as the cap loads the spring which keeps the armature end float under control and end float is crucial on those beasts. A discharge with the switch on is a bit odd but perhaps you have an old battery excited alternator. Any pictures possible? Written description of starter and alternator? Numbers?

[Timleech]

This is interesting. Screw on cap with a spring inside? The only starter that leaps to mind is the CAV CA45 which seems a bit of overkill for a 2 cyl Lister. If that is the case, it really needs that cap as the cap loads the spring which keeps the armature end float under control and end float is crucial on those beasts. A discharge with the switch on is a bit odd but perhaps you have an old battery excited alternator. Any pictures possible? Written description of starter and alternator? Numbers?

 

The CA45 was standard on the H series Listers, common in bigger/working Narrow Boats.

Is it one of those?

 

Tim

[twinpot]

The CA45 was standard on the H series Listers, common in bigger/working Narrow Boats.

Is it one of those?

 

Tim

Yes you are right its a HW2,I should have taken details of what make the starter motor was,do you know where i could pick up one of those end caps ,appologies to Blodger as i led him to believe it was air cooled.I shall not be able to have access to a computer till Sunday night,so will not be able to reply to any posts till then. thanks for everyones help so far.

kind Regards.

Twinpot.

 

This is interesting. Screw on cap with a spring inside? The only starter that leaps to mind is the CAV CA45 which seems a bit of overkill for a 2 cyl Lister. If that is the case, it really needs that cap as the cap loads the spring which keeps the armature end float under control and end float is crucial on those beasts. A discharge with the switch on is a bit odd but perhaps you have an old battery excited alternator. Any pictures possible? Written description of starter and alternator? Numbers?

Sorry,but i wont be able to get to the boat for at least six weeks do to work, but i think you are probably right about it being a CAV CA45.

[Sir Nibble]

Yes you are right its a HW2,I should have taken details of what make the starter motor was,do you know where i could pick up one of those end caps ,appologies to Blodger as i led him to believe it was air cooled.I shall not be able to have access to a computer till Sunday night,so will not be able to reply to any posts till then. thanks for everyones help so far.

kind Regards.

Twinpot.

 

 

Sorry,but i wont be able to get to the boat for at least six weeks do to work, but i think you are probably right about it being a CAV CA45.

I would suggest you go sniffing around an auto electrical repair specialist. You will need the cap, also a top hat shaped device that goes inside, a steel ball and unless it's still there, a spring. Alternatively, go hunting round a scrappy, those parts are the same for all CA45 starters of whatever voltage and application.

Edited to add: Are you SURE those bits aren't rolling around the bilge?

Edited March 5, 2010 by Sir Nibble

[twinpot]

I would suggest you go sniffing around an auto electrical repair specialist. You will need the cap, also a top hat shaped device that goes inside, a steel ball and unless it's still there, a spring. Alternatively, go hunting round a scrappy, those parts are the same for all CA45 starters of whatever voltage and application.

Edited to add: Are you SURE those bits aren't rolling around the bilge?

Yes im sure,the engine sits in its own room,and the bilge is painted white,and is clean,unless it flew off at speed.I will have a really good look when i get up there again,once again thanks everyone for your imput.

Kind Regards.

Twinpot.

[twinpot]

When you say lister twinpot I am presuming air cooled and no gloplug/heaters as a starting aid. If there are any of the latter they use a fair few amps and cause a related voltage drop. It sounds as though the starter isolation switch has something else on it, as an ignition circuit, perhaps a duff relay for something although it sounds as though you have attempted to trace the circuits and found nothing. Starter should not draw any current unless and until the solenoid is activated to start it.

 

I wonder if the volts on starter battery were falling because it was commoned with domestic batteries (which were much lower)by the 1/2/both switch at the time you were measuring and it was incidental nor causal that you 'switched on' the starter motor circuit?

Just to up date this thread,you were right blodger,i had got the 1/2/both switch on both,so the starter battery was equalizing with the domestic batteries hence the volt drop. Just goes to show,you should always think out of the box.

Thanks again to all.

Twinpot.

[blodger]

Just to up date this thread,you were right blodger,i had got the 1/2/both switch on both,so the starter battery was equalizing with the domestic batteries hence the volt drop. Just goes to show,you should always think out of the box.

Thanks again to all.

Twinpot.

Glad you have got it figured out.

 

A wooden working boat I have been involved with just used the 1/2/both to connect the batts.

 

Most boats and I would have thought yours would employ a relay or diodes in the starter circuit (to common with domestics) to ensure that the commoning does not happen until the alt is running (maybe using output from the charge warning connection to operat the relay) so that discharge starter to domestics does not happen.

 

If you have such diodes or relay the starter batt would benefit from having its own isolator switch since the current 1/2/both is defeating the purpose of said diodes/relay.

 

Nothing wrong with the 1/2/both without diodes/relay as long as you realise its shortcomings. A benefit is it reduces the number of connections that introduce resistance causing volts drop and avoids a relay that can burn out or diodes that also introduce a volts drop that reduces charging current to the domestics where you want it.

 

Hope that does not confuse you. The smartguage site explains it better!