rel External ControllerBack To Basics - AC5 Alternator with Kestrel External Controller

[alan_fincher]

OK - I already have a fairly long thread about the AC5 alternator in Flamingo, and the "miles" of dodgy confusing wiring associated with it, and the engine electrics generally.

 

I'm starting a new thread to bring it back to basics, as I still haven't fully worked out what is going on.

 

We have established that at some stage the alternator that used to have an external regulator has been modified to have an inbuilt one - this I think probably explains the presence of some cables in looms that now serve no useful purpose, and which are further clouding exactly what connects to what (Based on previous replies, I believe this action has effectively changed an AC5 alternator into an AC5R one?)

 

The back of the alternator when uncovered now looks like this.....

 

Now previously it was commented that an alternator with an internal regulator would only have 3 connections, namely, (I assume)......

 

Current out (sometimes signed B+)

Earth (sometimes signed D- ?)

Warning light (sometimes signed D+)

 

(THe negative earth is an actual connection, rather than relying on just using the body of the alternator).

 

But surely if using a Kestrel controller, then there has to be a 4th connection, (either originally present or added to an alternator not initialy having it). I think this adds......

 

"Field" or "Control Field" (which I believe is sometimes signed DF ?).

 

If I am correct, then apart from the obvious places the first three connections listed should be wired in to, then I expect a 4th wired directly to the output from the Kestrel, in order that it is able totake over and externally control the charge rate.

 

This would explain the 4 wires I have, even though tracing them is proving a challenge because the D+ and DF ones must all end up amongst a loom which by that point consists of nothing but fairly identical red wires.

 

Could the experts please confirm my logic above is correct, or (alternatively!) please point out where I have made any wrong assumption.

 

Thank you!

[nicknorman]

I've just had a large Pegu Club having made it round from Pelsall to Brum Central via old main line, so my thinking is as cloudy as my Pegu club but many alternators have a 4th connection namely W+ which is an AC feed to a tachometer.

[matty40s]

Alan, I have had a good look at that, followed the wires(tried to follow the wires) and...

I havn't a clue. Something has been overcomplicated beyond normal by wires that change from yello to red and then (maybe) back again, the black thing in the middle MAY be the new regulator, but also, it may not.

Hope Sir Nibble is still looking although............

[alan_fincher]

I've just had a large Pegu Club having made it round from Pelsall to Brum Central via old main line, so my thinking is as cloudy as my Pegu club but many alternators have a 4th connection namely W+ which is an AC feed to a tachometer.

 

Correct, but equally many older ones, (and this one looks old!), I think need modification to add such a wire.

 

I don't believe I have one, and there is certainly nothing as high tech as a tachometer, (none of the gauges typically added to any oldworking boat are really visible on the move, as all are generally in the engine room, with the possible exception of an oil pressure gauge externally on the engine room roof).

 

My question really is that I can't see how the external Kestrel controller can hope to do anything, unless there is at least one connection in addition to the minimum of three required by a modern alternator using an internal regulator.

[alan_fincher]

the black thing in the middle MAY be the new regulator, but also, it may not.

The black thing in the middle is without a doubt a regulator.

 

This is a 24 volt example, (seems nearly all advertised are?), but otherwise I'm sure similar

 

Linky

Edited April 19, 2015 by alan_fincher

[nicknorman]

Ok well just because the boat doesn't have a tachometer doesn't mean the alternator isn't capable of running one. However I suspect you're right and it isn't.

 

Why not tell us the voltage present on each of the connections when the engine is running and the batteries are nearly fully charged. If one of the wires is the relevant connection for a remote regulator (ie one of the rotor brush connections) it will have an intermediate voltage. The others would be expected to be at either 0v or 12v (ie the charging voltage which will of course not be 12v but hopefully around 14v+). The external regulator's wire's voltage will change substantially with alternator load.

 

Anyway, have you explained what is behind your question - what are you actually trying to achieve?

 

Hopefully snibs will be along to put us right but unfortunately i fear not.

 

Ed: following your latest post of course if it's a 24v system then the voltages I mention are x2

Edited April 19, 2015 by nicknorman

[alan_fincher]

Anyway, have you explained what is behind your question - what are you actually trying to achieve?

Before there was an issue with it not charging at all, even when increasing the current flowing through the warning light with an external resistor. Matty and I were only able to force it into charging by the sledgehammer approach of shorting temporarily across the warning light.

 

I seem to be doing better than that now. Whilst delving into a junction box where the entire loom has been lengthened I did find a couple of screws not fully tightened on to the wires beneath, but I'm not confident they are wires directly connected to the alternator, as all are red by this stage - it may be though that this is what has improved things, but equally it may not.

 

Now I'm trying to produce an accurate circuit diagram of everything I currently have, so I have a chance of doing quicker diagnoses when things are not working. Ultimately it would benefit from a new loom (as a minimum), but I need to be able to run the engine and charge batteries now, without spending days on a full rewire.

 

Anyway I do not want to attempt a full rewire, unless I understand where things are currently connected. I know it sounds like it should be easy to work out for each cable which ends belong to the same connection, even if they are (say) green at one end, and red at the other - simply disconnect likely candidates, and test for continuity. Unfortunately many of the connections are made in insulated crimps, so I can neither easily disconnect them, or get a probe on them. The wires are in many cases not long enough to allow e to cut those crimps out, then subsequently remake the join.

 

At this stage I just want to be sure that if there is a Kestrel, then there must be an additional wire from it into the alternator that would not otherwise be required. I think I have convinced myself, but a second or third opinion would help.

Ed: following your latest post of course if it's a 24v system then the voltages I mention are x2

 

It would be nice, wouldn't it, but I'm very aware of always looking for his advice, but not being able to do anything to return his continual generosity.

 

If he has decided the forum is not the place to be whilst his life is as it is, then I fully respect that. I can't pretend to imagine how anybody deals easily with some of the crap that has been handed down to him - the "cuckoo baby" ordeal had a simply awful outcome

[nicknorman]

So (in the accepted absence of the expert) the underlying problem is "better" at the moment but you want to future proof further problems by understanding how it hangs together?

 

So I come back to my point about identifying what each wire does by its voltage. All 4 wires in your photo have exposed metalwork so the voltage can easily be determined. Try it with the "ignition" on and the engine not running, then (as I said previously) with the engine running and the batteries well (but not fully) charged - or fully charged but with a significant load on (tunnel light etc). That will allow us to determine what each wire does.

[alan_fincher]

Not back there for a while, (and I knew I should not have wrestled that horrible cover back over all those connections!).

 

Will try and take some measurements when next there.

 

In the meantime if anybody can fault the "logic" in my initial post, I'd like to know - thanks!

[Roger Crown]

Hi Alan

 

Give Peter Hopley a call he makes / made the Kestrel controller

and may be able to guide you.

Tel & Fax: 0161 336 2680---------Mob: 07711 496177