alternator change

[Ian F B]

Hello,Im in the process of helping a friend of mine do up his Springer,no sniggering!!!!.What started as converting the dining table from face to face to L shape ,has escalated into a full windows out refit.During this arduous task the alternator decided it had lost the will to charge and we were informed by the very nice man at the reconditioners it was not repairable due to its age.I think I can identify the dud one as an 11 A C,this apears to have had a seperate rectifier and regulator whereas the new one which is a lucas A127 obviouslyhas both these functions on it.

I need to know if anyone has had experience of this swap and would they care to share it with me?

I do have experience of restoring cars and motorcycles and after 25 years as a TV /Video engineer I do know one end of a voltmeter from the other.If any one is interested I have picked up a few tips while doing this refit so any queries on window removal etc,Id be only to happy to share.

Cheers Ian F B >

[dave_2A_]

http://www.roversnorth.com/store/t-technic...alternator.aspx

 

if it's of any use....

[SteveE]

Hello,Im in the process of helping a friend of mine do up his Springer,no sniggering!!!!.What started as converting the dining table from face to face to L shape ,has escalated into a full windows out refit.During this arduous task the alternator decided it had lost the will to charge and we were informed by the very nice man at the reconditioners it was not repairable due to its age.I think I can identify the dud one as an 11 A C,this apears to have had a seperate rectifier and regulator whereas the new one which is a lucas A127 obviouslyhas both these functions on it.

I need to know if anyone has had experience of this swap and would they care to share it with me?

I do have experience of restoring cars and motorcycles and after 25 years as a TV /Video engineer I do know one end of a voltmeter from the other.If any one is interested I have picked up a few tips while doing this refit so any queries on window removal etc,Id be only to happy to share.

Cheers Ian F B >

 

Hi Ian and welcome.

There's loads already on the forum about A127s, performance, connections, requirements, etc. Have a go at the search facility to pick the information up.

Regards

SteveE

[Maverick]

Hello,Im in the process of helping a friend of mine do up his Springer,no sniggering!!!!.What started as converting the dining table from face to face to L shape ,has escalated into a full windows out refit.During this arduous task the alternator decided it had lost the will to charge and we were informed by the very nice man at the reconditioners it was not repairable due to its age.I think I can identify the dud one as an 11 A C,this apears to have had a seperate rectifier and regulator whereas the new one which is a lucas A127 obviouslyhas both these functions on it.

I need to know if anyone has had experience of this swap and would they care to share it with me?

I do have experience of restoring cars and motorcycles and after 25 years as a TV /Video engineer I do know one end of a voltmeter from the other.If any one is interested I have picked up a few tips while doing this refit so any queries on window removal etc,Id be only to happy to share.

Cheers Ian F B >

 

Hi Ian I recently had to do the exact very same thing. The swop is straightforward. The old alternator charged at around 35amps and yr new one should charge at about 55amps (tho figures quoted are 70amps)

 

Only prob I had was getting it charging when I first fixed it on. I'm convinced now that this was due to having a one cylinder slow revving engine as Snibble will testify to. So give it plenty of revs and you shouldnt have a problem.

 

Oh and I dispensed with the thick brown wire cus my old alt had 3 wires and I now only have 2 in place. Works fine.

[Sir Nibble]

The 11ac is a six diode unit excited from an ignition supply attenuated through an external regulator. There is a small hot wire unit powered up off the alternator winding star point purely to function the warning light. Locate the regulator and warning light unit and launch carefully at the bin. Isolate and make safe the live to the regulator. Identify the lead to the warning light unit that comes from the warning light, and the one from the alternatot star point, connect them together where the warning light unit used to be, and to the D+ on your new alternator. Connect the main +ve and that should be that.

An A127 may be rated at 45, 55, 65, 70 or 72 Amps.

[Ian F B]

Many thanks for the replies,very helpful,upon further Googling I found two good sites which were useful,www.kampenwagen.co .uk,this shows how to wire in a split charge relay in non techspeak,and www.tb training.co.uk,this has sections on all aspects ofboat electrics including diagrams showing common alternator types and the correct connection points.Enjoy!!!!

Cheers Ian F B .

[Tony Brooks]

The 11ac is a six diode unit excited from an ignition supply attenuated through an external regulator. There is a small hot wire unit powered up off the alternator winding star point purely to function the warning light. Locate the regulator and warning light unit and launch carefully at the bin. Isolate and make safe the live to the regulator. Identify the lead to the warning light unit that comes from the warning light, and the one from the alternatot star point, connect them together where the warning light unit used to be, and to the D+ on your new alternator. Connect the main +ve and that should be that.

An A127 may be rated at 45, 55, 65, 70 or 72 Amps.

 

 

Not arguing with you, but some 10/11 ACs in later years did not use the hot wire (flasher unit can) type warning lamp control. They used a large plastic covered relay (case a bit smaller that a two bobbing regulator) that closed as the alternator went on charge and thus shorted the warning lamp out (I think - its so long ago its hard to remember). I thought the relay number was 16RA, but recently I discovered that number now produces what I called a 6RA metal case relay.

 

I am only saying this in case someone tries the conversion and gets worried by the thing.

 

Now to Ian

 

My advice would be to cut back and insulate all the existing wires to the alternator, the square control box and any warning lamp control and then rewire from scratch. You will have to upgrade the main charging cables anyway because the new alternator will have close to twice the output.

 

Remember the "bush" in the back bracket of many alternators can be tapped through the bracket so the gap between brackets suits a particular engine - but for goodness sake support the underside of the bracket - otherwise you may snap it.

 

Lastly, I see no reason not to use a scrap alternator from a car, then only thing is that it will be earth return - just like the starter and glowplugs - and if the only output terminals are two 9mm blades please split the charging cable and fit two female connectors so you take the charge off both blades and not one.

 

Tony Brooks

[Jim Riley]

Lastly, I see no reason not to use a scrap alternator from a car,

 

Tony Brooks

 

or better still, a working alternator from a scrap car

[Ian F B]

Once again thanks fur your help,prior to revisiting this site I set to with my trusty voltmeter and and a roll of insulating tape.With a wiring diagram from a well known book on how to fit out a narrowboat,I proceeded to follow the circuit diagram.Two hours later,engine on,charge light glowing,start her up,no charge ,no light going out!!!!.

On checking the wiring with my meter I noticed a 5.6 volt drop across the charge light,then it all became clear,the relay to switch from engine to leisure battery was connected directly to the alternator charge light output terminal,so of course as soon as the alternator powered up the relay,the 12 volt required to power up the alternator went down to4.4 volts,so no charge!!.

A quick temporary rejig,which involved fitting a temporary engine/leisure switch soon had the system charging like a mad elephant,and normal service was resumed.

The wiring diagram in question,is in my opinion not sound,unless you can find a relay that takes zero current on switch on and hence causes no voltage drop,perhaps a solid state relay using microprocessor control is the answer?

Cheers Ian F B .

[Guest]

Once again thanks fur your help,prior to revisiting this site I set to with my trusty voltmeter and and a roll of insulating tape.With a wiring diagram from a well known book on how to fit out a narrowboat,I proceeded to follow the circuit diagram.Two hours later,engine on,charge light glowing,start her up,no charge ,no light going out!!!!.

On checking the wiring with my meter I noticed a 5.6 volt drop across the charge light,then it all became clear,the relay to switch from engine to leisure battery was connected directly to the alternator charge light output terminal,so of course as soon as the alternator powered up the relay,the 12 volt required to power up the alternator went down to4.4 volts,so no charge!!.

A quick temporary rejig,which involved fitting a temporary engine/leisure switch soon had the system charging like a mad elephant,and normal service was resumed.

The wiring diagram in question,is in my opinion not sound,unless you can find a relay that takes zero current on switch on and hence causes no voltage drop,perhaps a solid state relay using microprocessor control is the answer?

Cheers Ian F B .

I have mentioned it before, but I was advised by a Vetus agent not to connect a relay in this manner. Not sure which alternators this applies to though. I eventually used one which senses the voltage across the start battery, and switches the relay in when it reaches sufficient voltage (usually about ten seconds). It has worked extremely well for the best part of 4 years now.

[chris w]

The 11ac is a six diode unit excited from an ignition supply attenuated through an external regulator. There is a small hot wire unit powered up off the alternator winding star point purely to function the warning light. Locate the regulator and warning light unit and launch carefully at the bin. Isolate and make safe the live to the regulator. Identify the lead to the warning light unit that comes from the warning light, and the one from the alternatot star point, connect them together where the warning light unit used to be, and to the D+ on your new alternator. Connect the main +ve and that should be that.

An A127 may be rated at 45, 55, 65, 70 or 72 Amps.

 

.............and 80A as I have two such beasts on my boat. Or at least they're marked as such.

 

Chris

[John Orentas]

The wiring diagram in question,is in my opinion not sound,unless you can find a relay that takes zero current on switch on and hence causes no voltage drop,perhaps a solid state relay using microprocessor control is the answer?

Cheers Ian F B .

 

 

 

Ian.

 

You are not quite right in all this, the point is that the charge light output on your alternator is rather more than an on/off output, it actually changes from a positive voltage to ground.

 

So the idea is that you connect your relay with a permanent +volts on one side of the coil and the alternator warning light output on the other side, in that way when the alternator output is 'off' (zero volts), the relay is energised, when the alternator output is 'on' the voltage on both sides of the relay coil are equal and the relay de-energises. In other words when the charge light is on, the relay is out, and visa-versa.

 

This is the bit that foxes so many people.

Edited November 3, 2007 by John Orentas

[chris w]

JO is correct about the D+ output but it doesn't matter that it works this way round as all normal relays will have both NO (normally open) and NC (normally closed) contacts so just choose the approriate contacts to make it work correctly.

 

Chris

[John Orentas]

JO is correct about the D+ output but it doesn't matter that it works this way round as all normal relays will have both NO (normally open) and NC (normally closed) contacts so just choose the approriate contacts to make it work correctly.

 

Chris

 

 

Don't quite go along with that either, remember the relay contacts must close when the alternator begins to output (when the engine is running and the starter has done it's job), you must be careful the the battery banks are not connected together until the alternator is outputting.

 

Just changing the polarity and N/c and N/o configuration will not ensure the above at all times.

Edited November 3, 2007 by John Orentas

[Sir Nibble]

Ian.

 

You are not quite right in all this, the point is that the charge light output on your alternator is rather more than an on/off output, it actually changes from a positive voltage to ground.

 

So the idea is that you connect your relay with a permanent +volts on one side of the coil and the alternator warning light output on the other side, in that way when the alternator output is 'off' (zero volts), the relay is energised, when the alternator output is 'on' the voltage on both sides of the relay coil are equal and the relay de-energises. In other words when the charge light is on, the relay is out, and visa-versa.

 

This is the bit that foxes so many people.

Hang on a minute, go previous, are we still talking about an 11ac here? That alternator has no warning light terminal as such, just an ac output taken from the stator winding. It goes from zero at rest to around 7V ac when charging.

[Ian F B]

Reference alternator problems,we are now talking about usjng a Lucas A127,and to clarify further,my qbservation was that the diagram I was using was suspect,as after connecting up as per the diagram it didnt bloody work,and after looking at the problem and rewiring it did.The basic principle of the alternator is a an electric motor in reverse,you energise the coil,and the mechanical rotation of the engine generates anA C voltage which is rectified by the diode pack and then fed as D C to the battery ccts etc.It is this voltage that is returned to the alternator side of the charge light that causes the light to extinguish as there is now 12 volts on both sides of the light,no potential difference,no current flow,no light,simple really.

Cheers Ian F B

[Ian F B]

Reference your thougts on relays,a relay is simply an electrically operated switch,a current/voltage is passed through a coil which energises and closes a pair of contacts which allows a larger current,in this case the battery charge to flow into the battery.

The basic connections for arelay are as follows;

86 warning,charge light,

85 earth,

30 start battery,

87 leisure battery.

these connections are all marked on the relay and follow standard vehicle wiring codes.

The use of relays allows a small current to switch a large current,hence saving on the use of large cables which are obviously more costly.

Hope this clears up any confusion,

Cheers,Ian F B .

[chris w]

Note that some relays will have an additional (5th) terminal marked 87a. Do NOT use this one by mistake instead of terminal 87 for battery paralleling circuits.

 

Chris

[Ian F B]

Note that some relays will have an additional (5th) terminal marked 87a. Do NOT use this one by mistake instead of terminal 87 for battery paralleling circuits.

 

Chris

[Ian F B]

Chris,It is possible to use 87a,it depends on what type of relay it is

If its a 5 blade changeover this will switch the voltage from 87a to 87

If its a 5 blade double make or break this will allow you to use either 87 or 87a or both

If its a 5 blade twin make and break both 87 and 87a are joined internally so either can be used.

With regard to all things electrical,I can personally recommend Vehicle Wiring Products for quality and service.There catalogue is very good and shows diagrams of all the usual types of relays.

Happy Boating and Ill try to post some photos of the Springer,(boat not dog) when its looking alittle less of a wreck.

Cheers,Ian F B.

[chris w]

Since most people won't know one relay from another, it's therefore best to totally avoid 87a as I suggested.

 

Chris