Alternator beta 43

[dave mackie]

My engine battery alternator does not 'excite' and it doesn't charge. If I keep starting engine then turn off engine a few times the starter motor starts clicking and not turning the engine (battery dead). However if I then jump start the battery the engine will start and alternator will charge. Any ideas peeps 

[BEngo]

Flat and knackered starter battery.  If you can charge it off the mains for at least 24 hours.  It takes much longer than many folk think to refill a battery.  Once charged leave it for an hour with the charger off and then check  the terminal voltage. It should be about 12.7 v. 

 

Poor connections in the starter circuit.  Check they are all clean and tight.

 

The  alternator needs 12V to get itself going.  If the start battery is duff there may well be not enough volts to excite it.  Once it is going it will keep itself going, hence why it works when jump started.

 

N

[Tony Brooks]

6 minutes ago, BEngo said:

Flat and knackered starter battery.  If you can charge it off the mains for at least 24 hours.  It takes much longer than many folk think to refill a battery.  Once charged leave it for an hour with the charger off and then check  the terminal voltage. It should be about 12.7 v. 

 

Poor connections in the starter circuit.  Check they are all clean and tight.

 

The  alternator needs 12V to get itself going.  If the start battery is duff there may well be not enough volts to excite it.  Once it is going it will keep itself going, hence why it works when jump started.

 

N

 

That was my first thought, but he says "If I keep starting engine then turn off engine a few times the starter motor starts clicking". Unless he is not revving it enough after the start, I think that it should have energised. If the voltage is down but by a miracle it started, then maybe it requires rather more than usual revs to get it charging. I agree with all the rest.

[StephenA]

1 hour ago, dave mackie said:

My engine battery alternator does not 'excite' and it doesn't charge. If I keep starting engine then turn off engine a few times the starter motor starts clicking and not turning the engine (battery dead). However if I then jump start the battery the engine will start and alternator will charge. Any ideas peeps 

 

So if you jump it then the alternator excites and the no charge light goes off but it doesn't go off if you start the engine without jumping? As Tony says does the no charge light go off if you increase the revs?

[dave mackie]

Cheers for your thoughts guys. When I started engine before battery died I was revving the engine hard but alternator still didn't start charging. It wasn't until I had to jump start it that the alternator started to charge making me think that the alternator was not being 'excited' by the battery until I jumped it with fully charged one( making me think that battery did not have enough juice in it to excite alternator originally).

2 minutes ago, StephenA said:

 

So if you jump it then the alternator excites and the no charge light goes off but it doesn't go off if you start the engine without jumping? As Tony says does the no charge light go off if you increase the revs?

That's correct 

The charge light stays on when revving engine, also rev counter does not work 

[Tony Brooks]

Just now, dave mackie said:

Cheers for your thoughts guys. When I started engine before battery died I was revving the engine hard but alternator still didn't start charging. It wasn't until I had to jump start it that the alternator started to charge making me think that the alternator was not being 'excited' by the battery until I jumped it with fully charged one( making me think that battery did not have enough juice in it to excite alternator originally).

 

The point is that the alternator "excite" circuit draws less than 1 amp, whereas the starter draws well over 100 amps (probably hundreds) so if the engine starts there should be enough "charge" left in the battery to excite the alternator. I think this is probably a bad connection somewhere, depending upon how the boat is wired I would be looking at all the battery terminals (are the clamps and posts, or whatever clean, bight at the mating surfaces and tight? Pay particular attention to where the engine and domestic battery negatives join because I suspect the act of jumping may move something slightly.

 

Check all the terminals on the alternator for cleanliness and tightness.

 

This sounds like a bit of an odd one, do you have any form of alternator controller in use.

[dave mackie]

No remote alternator controller used. Twin alternators only.

[Tony Brooks]

1 minute ago, dave mackie said:

No remote alternator controller used. Twin alternators only.

That rules one thing out, then. Thanks.

[Tracy D'arth]

Its a Beta, check the multiplugs on the engine wiring loom for bad contacts.

[dave mackie]

I thought that as well so I had new multi plug fitted.

I think I'll have to check wiring from battery to starter motor. There's a connecting block that's bolted to engine bearer that's a pig to get at that I haven't looked at yet

[ditchcrawler]

I would suggest the battery isolator giving a high resistance after passing the starter current so not powering the "ignition" light. Does the "ignition" or "alternator charging light" what ever you want to call it, come on before starting the engine on its own battery  and go out or stay on after starting?

 

[dave mackie]

New isolator fitted. When ignition is turned on the charging light is on.when engine starts the charging light stays on 

[TheBiscuits]

1 hour ago, Tracy D'arth said:

Its a Beta, check the multiplugs on the engine wiring loom for bad contacts.

 

Also see if there's two multiplug connections! 

 

I've been caught out by this before - there's sometimes an extended harness between the multiplug from the engine and the multiplug from the control panel.

 

It depends how the engine installation was done.

 

 

[Rincewind]

Have you considered that maybe the carbon brushes and/or the slips ring are worn, (or both!) causing intermittent excitement (or non excitement) of the rotor coils?

[Tony Brooks]

6 hours ago, Rincewind said:

Have you considered that maybe the carbon brushes and/or the slips ring are worn, (or both!) causing intermittent excitement (or non excitement) of the rotor coils?

 

On 9 diode machines, as I think the Beta alternators are, that would result in no charge and no warning lamp. In effect, the warning lamp earths through the brushes.

 

I don't know how it fits the symptoms, but if the circuit between engine battery positive and the warning light goes resistive, then the alternator will back feed the instruments via the warning amp which would be on, but the battery would be charging. I don't think this can be the case here, but I do think a voltage check before and after staring across the engine battery would be a good idea - and tell us the result.

 

If there is one warning lamp, or two warning lamps but no relay, then diagnosis in far more complicated.

[nicknorman]

13 minutes ago, Tony Brooks said:

 

On 9 diode machines, as I think the Beta alternators are, that would result in no charge and no warning lamp. In effect, the warning lamp earths through the brushes.

 

I don't know how it fits the symptoms, but if the circuit between engine battery positive and the warning light goes resistive, then the alternator will back feed the instruments via the warning amp which would be on, but the battery would be charging. I don't think this can be the case here, but I do think a voltage check before and after staring across the engine battery would be a good idea - and tell us the result.

 

If there is one warning lamp, or two warning lamps but no relay, then diagnosis in far more complicated.

The Beta 43 has been around for a while so it’s hard to be categoric, but for recent ones with twin alternators, the starter alternator is a 6 diode machine. It certainly is on our 2010 engine.

 

So there is an “IGN” wire that wakes the alternator up when 12v is applied, and a separate warning light wire. The field current is initially obtained from the B+ wire.

 

So it with the warning light being on, this suggests that both that wire and the IGN wire and the B+ are all connected, pointing to an internal alternator fault (intermittent, eg worn brushed).

 

Before removing the alternator I would check voltages on the alternator terminals with ignition switched on, should be 12v on B+ (fat wire) and IGN (brown wire), and 0v on warning light wire (brown/yellow). If that is all satisfactory I can’t see another explanation other than a faulty alternator-

[Tony Brooks]

Agree, but still can't see how jumping from the domestic bank allows it to energise and run. I await with interest to see how this develops.

[nicknorman]

2 minutes ago, Tony Brooks said:

Agree, but still can't see how jumping from the domestic bank allows it to energise and run. I await with interest to see how this develops.

Yes that bit is a puzzle. I’m not clear if this was a one off thing, or a routine finding. If the former, perhaps it was just that eg worn brushes decided they would connect with the slightly higher system voltage. But if it is repeatable then yes it is definitely a puzzle. But still, if the voltages present on the alternator terminals are correct, it should charge, and if it doesn’t that points to a faulty alternator.

[dave mackie]

Cheers for the input peeps, the voltage checks on the  alternator and the connections on the distribution block on side of engine was my next checks. It just seems strange that putting a higher current from jump starting seemed to start the alternator to charge.

[Tracy D'arth]

13 minutes ago, dave mackie said:

Cheers for the input peeps, the voltage checks on the  alternator and the connections on the distribution block on side of engine was my next checks. It just seems strange that putting a higher current from jump starting seemed to start the alternator to charge.

That is the bit that makes no sense. I think there is something else happening that you are missing. Is there a voltage sensitive relay somewhere that connects the batteries to both alternators or even a plain relay?

I would suggest getting the alternator checked out to eliminate or prove it faulty.  Then move on from a stand of knowing what is or isn't faulty.

[dave mackie]

Both alternators are basic stand alone systems. There's no relays. One lower amperage for starter battery and a higher amperage for the domestic batteries. The domestic side is working perfectly so I'm sure there's no relays used between the starting and domestic charging systems  . I'll get the alternator removed and checked and while it's removed it will give me better access to the distribution block wiring for  the charging/starter motor .

[Tony Brooks]

13 minutes ago, dave mackie said:

Both alternators are basic stand alone systems. There's no relays. One lower amperage for starter battery and a higher amperage for the domestic batteries. The domestic side is working perfectly so I'm sure there's no relays used between the starting and domestic charging systems  . I'll get the alternator removed and checked and while it's removed it will give me better access to the distribution block wiring for  the charging/starter motor .

 

What you say about two stand-alone systems is most likely true, but one would expect the domestic alternator warning lamp to be energised via a relay that is controlled from the ignition switch. This only applies to the warning lamp circuit.

[dave mackie]

How I understand is that alternator warning light is energised when ignition is in on position feeding it with the 12v req for light to be on, then when ignition key is in start position it excites the alternator into charging mode and turn light out. I'll look for a relay but I'm sure there isn't one on the starter battery alternator. I have two independent charging lights for starter and domestic systems.

[Tracy D'arth]

3 minutes ago, dave mackie said:

How I understand is that alternator warning light is energised when ignition is in on position feeding it with the 12v req for light to be on, then when ignition key is in start position it excites the alternator into charging mode and turn light out. I'll look for a relay but I'm sure there isn't one on the starter battery alternator. I have two independent charging lights for starter and domestic systems.

Nearly.

 The ignition puts 12v on the warning lamp which earths via the non rotating alternator, it lights up and feeds energising current to the alternator.

When the alternator starts to produce charge current, the lamp is then fed 12v from the alternator and as it has 12v on both wires, there is no current flow and the lamp goes out.

[StephenA]

21 hours ago, dave mackie said:

Cheers for your thoughts guys. When I started engine before battery died I was revving the engine hard but alternator still didn't start charging. It wasn't until I had to jump start it that the alternator started to charge making me think that the alternator was not being 'excited' by the battery until I jumped it with fully charged one( making me think that battery did not have enough juice in it to excite alternator originally).

That's correct 

The charge light stays on when revving engine, also rev counter does not work 

 

When you jump it and the light goes off does the Rev Counter start working?