Alternator

[Maverick]

I dont know if you can help with this one. I had a brand new alternator in a box of bits that came with the boat. All the mounting fixings are identical to my old lucas alternator but there are a few different connections on the back of this alternator. (Now believed to be a 70 amp lucas A127. Thanks to Mark)

 

It still has the original block of 3 like my old lucas but also has a connection marked B+ one marked W and a small spade connection beneath the one marked B+.

 

I tried fitting it just using the block of 3 connections but could not get it to work and am just wondering if changing or adding a few wires might do the trick.

 

Any ideas?

 

Edited August 27, 2007 by Maverick

[Amicus]

Stay calm, tis a boaty weekend, everybody's out playing.

There are a couple of members who will kno all about your kit. The Rite Hon. Snibble will tell all, including the alternator's inside leg measurement.

I can tell you the W terminal is to drive a tacho and ..........ummm................thass all I kno.

 

 

edit:- meanwhile Tony Brooks' site might help

http://www.tb-training.co.uk/

always worth studying in any case

 

try here

http://www.tb-training.co.uk/MarineE08.htm...96%20ALTERNATOR

Edited August 27, 2007 by Amicus

[Maverick]

Stay calm, tis a boaty weekend, everybody's out playing.

There are a couple of members who will kno all about your kit. The Rite Hon. Snibble will tell all, including the alternator's inside leg measurement.

I can tell you the W terminal is to drive a tacho and ..........ummm................thass all I kno.

edit:- meanwhile Tony Brooks' site might help

http://www.tb-training.co.uk/

always worth studying in any case

 

try here

http://www.tb-training.co.uk/MarineE08.htm...96%20ALTERNATOR

 

 

Ha ha. I too would be out boating if my problem was sorted. Did look at the TB site and wondered if putting a wire from the B+ to the battery would work, but would I still leave the 3 block connecting wires connected? Questions questions. How dare they all go bloody boating, do they think this is a hobby or summut?

[ChrisPy]

.....wondered if putting a wire from the B+ to the battery would work,

.................. suggesting that you haven't yet connected B+ to the battery positive. it would help - that is the main feed to the battery. and of course it needs a heavy cable.

 

PS: if you energise the alternator but have not connected it to the battery you could do serious damage to the alternator. it must be connected to a load.

Edited August 27, 2007 by chris polley

[Maverick]

.................. suggesting that you haven't yet connected B+ to the battery positive. it would help - that is the main feed to the battery. and of course it needs a heavy cable.

Just had another look at it Chris and just come to the same conclusion. Think I need to take my original output lead and swop the spade end for a ring connecter and apply it to to B+ as the two large terminals in the block of 3 appear to be linked together, though not sure why you would want to connect 2 input wires into the alternator. Sure Snibble will tell me.

.................. suggesting that you haven't yet connected B+ to the battery positive. it would help - that is the main feed to the battery. and of course it needs a heavy cable.PS: if you energise the alternator but have not connected it to the battery you could do serious damage to the alternator. it must be connected to a load.

I did and have a feeling I may have knackered this new alternator as Im now guessing I had the original input and output wires connected together. Oh well we live n learn. I'll go try it again and keep my fingers crossed.

[Maverick]

Looks like I may have fried it or the previous owner beat me to it.

 

So does anyone have a Lucas 17/18 ACR for sale? Does anyone know if the connections are the same on the 17 & 18 models? I'm assuming they may be and that the 18 just has a greater output.

 

My original may even be a 16 I have no way of telling.

 

 

Edited to add:- I assume you have to pay just to get these alternators checked do you? If so may as well just put the money towards another.

Edited August 27, 2007 by Maverick

[John Orentas]

Hi Mave.

 

I think that all you need to connect is the 'B' (heavy) terminal to the battery/s and it should work. All the others are for the 'charge light' rev counter etc.

 

Do you have a split charge relay, the problem could be just that. To try it take a wire (quite heavy) from 'B' direct to the battery and isolate everything else. All the negs should be left in place though.

 

A clamp meter would help.

Edited August 27, 2007 by John Orentas

[Maverick]

Hi Mave.

 

I think that all you need to connect is the 'B' (heavy) terminal to the battery/s and it should work. All the others are for the 'charge light' rev counter etc.

 

Do you have a split charge relay, the problem could be just that. To try it take a wire (quite heavy) from 'B' direct to the battery and isolate everything else. All the negs should be left in place though.

 

A clamp meter would help.

 

Hi John, no havnt a split charge relay fitted and have tried a wire off the B+. Pretty sure its knackered. The original lucas didnt have an earth wire so I assume it earthed through the mounting bracket. Not sure if this model needs an earth applying though.

[John Orentas]

Hi John, no havnt a split charge relay fitted and have tried a wire off the B+. Pretty sure its knackered. The original lucas didnt have an earth wire so I assume it earthed through the mounting bracket. Not sure if this model needs an earth applying though.

 

 

I'm sure you are right but try a wire from casing to battery neg. can't do any harm. The things are very repairable there are one or two firms local to me though I am sure Snibble is your best bet.

[KenK]

Maverick

 

B+ is the main positive connection to the battery.

W is a phase tap to allow you to run a tachometer.

 

The small spade under the B+ is probably D+ its an aux output for external control, you shouldn't need it.

 

One of the other three should be labeled F or DF this should be connected to the warning lamp, it energises the field winding to help the alternator start operating.

 

Anything labeled 61/Ind/L/Aux can be ignored for the moment more aux outputs.

 

Finally the alternator negative will probably be from the case , if not there will be another stud / spade labeled -B/-E/Gnd/Bat-

 

All you need for the alternator basic operation is +/- B ie to and from the battery and the field wire connection F. You may have already damaged it however many alternators have a surge diode to protect against operating without a load. Try the basic connections and see how you get on.

 

Good luck

 

Ken

[Maverick]

Maverick

 

B+ is the main positive connection to the battery.

W is a phase tap to allow you to run a tachometer.

 

The small spade under the B+ is probably D+ its an aux output for external control, you shouldn't need it.

 

One of the other three should be labeled F or DF this should be connected to the warning lamp, it energises the field winding to help the alternator start operating.

 

Anything labeled 61/Ind/L/Aux can be ignored for the moment more aux outputs.

 

Finally the alternator negative will probably be from the case , if not there will be another stud / spade labeled -B/-E/Gnd/Bat-

 

All you need for the alternator basic operation is +/- B ie to and from the battery and the field wire connection F. You may have already damaged it however many alternators have a surge diode to protect against operating without a load. Try the basic connections and see how you get on.

 

Good luck

 

Ken

 

Thanks Ken. Cofident I now know the connections and that the Alternator has been damaged.

 

Next question is what part is it likely to have been damaged? I ask this as I have located a new rectifier and a new regulator on ebay which both look relatively easy to fit (bet they not) and not badly priced if one or both are likely to solve the problem.

Would the surge diode be in one of these parts

Edited August 27, 2007 by Maverick

[John Orentas]

Thanks Ken. Cofident I now know the connections and that the Alternator has been damaged.

 

Next question is what part is it likely to have been damaged? I ask this as I have located a new rectifier and a new regulator on ebay which both look relatively easy to fit (bet they not) and not badly priced if one or both are likely to solve the problem.

Would the surge diode be in one of these parts

 

 

Hi Mave.

 

That is pretty much all there is a set of diodes that forms the rectifier and a regulator, Snibble too was offering those for just a few pounds. The only other components are the coils, I understand it is unlikely they would have been damaged. Both of the components are the sort of things that are easily destroyed by overload or reverse polarity.

 

If the price looks right I would be inclined to buy the new bits but make sure if you can that the regulator is rated at 14+ volts output.

Edited August 27, 2007 by John Orentas

[SteveE]

I dont know if you can help with this one. I had a brand new alternator in a box of bits that came with the boat. All the mounting fixings are identical to my old lucas alternator but there are a few different connections on the back of this alternator. (Now believed to be a 70 amp lucas A127. Thanks to Mark)

 

It still has the original block of 3 like my old lucas but also has a connection marked B+ one marked W and a small spade connection beneath the one marked B+.

 

I tried fitting it just using the block of 3 connections but could not get it to work and am just wondering if changing or adding a few wires might do the trick.

 

Any ideas?

 

Hi Maverick

We are in exactly the same position having dumped the black and unconnected ACR17 and bought a new a127. When I fitted our 'knackered' new alternator to our land rover it worked perfectly and was presumably not knackered because it was never energised to make it charge. The connector you mention is the Landy's form of connection to the alternator and the large spade connectors are an alternative to the B+ stud. Summat else is going on and I will be very interested to learn what!

Best regards

SteveE

[chris w]

Just read this thread. I have 2 x A127's on my boat and the connections are as follows:

 

You need to connect B+ to your battery and the smallest of the 3 spade connectors (the one nearest the B+) to the ignition light. This latter is the D+ connection; the other side of the ignition light should be connected to the battery through the ignition switch. The W is a connection for a tacho and the case is the negative. The other two spades are both connected internally to the B+ stud.

 

Chris

[Maverick]

Just read this thread. I have 2 x A127's on my boat and the connections are as follows:

 

You need to connect B+ to your battery and the smallest of the 3 spade connectors (the one nearest the B+) to the ignition light. This latter is the D+ connection; the other side of the ignition light should be connected to the battery through the ignition switch. The W is a connection for a tacho and the case is the negative. The other two spades are both connected internally to the B+ stud.

 

Chris

 

Hi Chris, you say connect the smallest of the 3 spades connectors (the one nearest B+) to the ignition light.

I take it you mean the smallest of the group of 3, as there is a small spade connecter right below the B+ stud which is actually closer to it.

so if I'm reading your thread correctly I dont connect any wires to the block of 3 spade connectors?

 

As I believed it I should have a thin energising wire going into the alternator via the ignition light, a Thick Brown feed into it from the ignition switch (which you havnt mentioned) and the B+ red wire going off the alternator to the battery.

 

Can you just confirm that I dont need to connect any wires to the block of 3 connecters and tell me where I connect the brown feed into the alternator please.

Edited August 28, 2007 by Maverick

[Sir Nibble]

Righto! The group of three connectors, the two large ones, and the large stud, and the small lucar by the stud are all B+ and connected internally. W is for the tacho and the small lucar in the group of 3 is the D+ warning light terminal. If you have a battery cable connected to any of the B+ connections, and a warning light to D+ the unit should work. If it's knackered, most likely (almost certainly) cause is the rectifier. It is not a difficult job to change it, but you will need a soldering iron around the 75W area. The brown wire from the ignition switch sounds like it might be a sense lead and is not required.

[mayalld]

Hi Chris, you say connect the smallest of the 3 spades connectors (the one nearest B+) to the ignition light.

I take it you mean the smallest of the group of 3, as there is a small spade connecter right below the B+ stud which is actually closer to it.

so if I'm reading your thread correctly I dont connect any wires to the block of 3 spade connectors?

 

As I believed it I should have a thin energising wire going into the alternator via the ignition light, a Thick Brown feed into it from the ignition switch (which you havnt mentioned) and the B+ red wire going off the alternator to the battery.

 

Can you just confirm that I dont need to connect any wires to the block of 3 connecters and tell me where I connect the brown feed into the alternator please.

 

Thick wire from B+ direct to battery (or to the battery isolator actually)

Thin wire to the D+ terminal from the ignition light

Tacho feed from the W terminal

 

The only ignition switched feed is via the warning light.

[Maverick]

Righto! The group of three connectors, the two large ones, and the large stud, and the small lucar by the stud are all B+ and connected internally. W is for the tacho and the small lucar in the group of 3 is the D+ warning light terminal. If you have a battery cable connected to any of the B+ connections, and a warning light to D+ the unit should work. If it's knackered, most likely (almost certainly) cause is the rectifier. It is not a difficult job to change it, but you will need a soldering iron around the 75W area. The brown wire from the ignition switch sounds like it might be a sense lead and is not required.

 

Thanks Snibbs that must mean it was already knackered then yet its brand new. When I originally connected my block of 3 to the 3 main spades I was in fact correct with the ignition feed wire and as the 2 big spades and the B+ are connected internally I did actually have a feed going to the battery so I wasnt running it off load as Chris suggested earlier.

 

That brings me back to my original worry. When I first kicked the engine in after connecting the new alternator the charge light went out and I thought I'd solved the problem. I stopped the engine and when I restarted it the light wouldnt go off.

[mayalld]

Thanks Snibbs that must mean it was already knackered then yet its brand new. When I originally connected my block of 3 to the 3 main spades I was in fact correct with the ignition feed wire and as the 2 big spades and the B+ are connected internally I did actually have a feed going to the battery so I wasnt running it off load as Chris suggested earlier.

 

That brings me back to my original worry. When I first kicked the engine in after connecting the new alternator the charge light went out and I thought I'd solved the problem. I stopped the engine and when I restarted it the light wouldnt go off.

 

Which implies that the first run knackered it

[Maverick]

Which implies that the first run knackered it

 

But Why? Bearing in mind I had just spent a week cruising wit my old Lucas ACR when its light came on on the last day of the trip. I assumed that was knackered and replaced it with this one.

Edited August 28, 2007 by Maverick

[mayalld]

But Why? Bearing in mind I had just spent a week cruising wit my old Lucas ACR when its light came on on the last day of the trip. I assumed that was knackered and replaced it with this one.

 

Too much current through the D+ is a possibillity

 

Turning off the battery master switch whilst the engine was running is another.

 

Anything that leaves an alternator turning over without the connections it expects is prone to cooking them.

 

Given that, trying to figure out connections by trial and error can be an expensive job, and it may work out cheaper to get somebody to come and do the job.

[Maverick]

Too much current through the D+ is a possibillity

 

Turning off the battery master switch whilst the engine was running is another.

 

Anything that leaves an alternator turning over without the connections it expects is prone to cooking them.

 

Given that, trying to figure out connections by trial and error can be an expensive job, and it may work out cheaper to get somebody to come and do the job.

 

The only thing that could make sense is that the Thick Brown wire which is suggested could be a sensing wire and which I had connected to one of the big spades which I now know to be linked to the B+ possibly sent 2 many volts/amps back upto the ignition switch and maybe back through the D+ wire then. Or is that just amateur technical bollocks

[Sir Nibble]

Or is that just amateur technical bollocks

Yup!

Perhaps the warning light cable has found a -ve somewhere, chafed on the metalwork or whatnot. Does the light come on if you turn on the ignition with the alternator disconnected?

[Maverick]

Yup!

Perhaps the warning light cable has found a -ve somewhere, chafed on the metalwork or whatnot. Does the light come on if you turn on the ignition with the alternator disconnected?

 

Will try and see but pretty sure there isnt a problem there. Plan to take both alternators to be tested today to make sure they are both knackered.

 

I like to learn from my mistakes and gain knowledge where ever posiible but I fear I am not going to learn why this alternator appeared to work first time and then appear knackered.

 

If it is knackered replacing or repairing it will be easy but when its reconnected is the same thing likely to happen again?

 

I will dispose of the main brown wire and just have the 2 wires attached next time the D+ and the B+ it may well work and be fine for years to come but I will never know why it happened so no lesson will be learned.

[bottle]

Maverick

 

I expect you have already done this, may I recommend that you check every millimetre of your wiring for faults, abrasion, loose connections etc.

 

This may have caused the problem in the first place.