[xj] more A133-75 alternator observations and challenges

My ~20 year old, rebuilt A133-75 finally failed about 5
years ago. A breaker yard spare went in. While it never
topped the volt meter scale to the exact point of the
previous one, it did manage to keep a full charge until last
weekend. Dash volt meter showing almost in the red
(12.6v’ish) with any accy turned on. The Fluke current probe
confirmed the problem: amperage maxed out at 20 amps,
regardless of load, even with engine revved a bit.
The real tell tale story here, IMO, is how well the alt
regulator performs at engine idle with some load (AC or
headlights) - you should see voltages on the dash gauge
remain near normal. Again IMO.
Yesterday, I installed yet another a breaker yard pull, a
Bosch reman that looked very new and clean. While this one
was capable of 45amps (briefly and only under certain
conditions as measured by the Fluke probe), the bloody
output voltage was sagging dreadfully under load (AC&
headlights on) to battery nominal voltage (12.6) or a bit
lower. Raising the RPMs off idle would barely lift the
voltage above 12.6v, again with full load. With accy’s all
turned off, voltage readings would eventually climb to 14.15
volts at idle.
IMO, this is the sort of Alternator behavior that can lead
you down the primrose path, until eventually it
self-destructs whilst struggling to charge a battery that
will, over time, ramp down to flat, given city driving with
some accy’s running. Also, this is the type of whimpy
charging pattern that leads to badly sulfated battery plates
over time. Unless you were to say, keep a ‘Battery Tender’
on it at all times when not driving, as I do now ;-). Truth
be told, I could prolly get by with this Bosch reman, for
quite awhile, given that I rarely drive the Series III XJ
anymore… the Battery Tender is therefore a way of life
for me now.
So, at my leisure, I’m chasing down a made in USA Transpo IL
219 (scarce) regulator, which is what was in the long lived
rebuild. It was matched to the diode stacks part # ILR 601
(all diodes tested perfectly - btw). Brushes still have
plenty of length…
XK’s Unlimited has an 80 amp regulator but I’m concerned
that it’s for the XJ40… OTOH, Alibaba has some Chinese
knock-offs and then there’s the made in Germany HUCO on
eBay. I will post back once I settle on a replacement
regulator. Oh and here’s hoping Sparx will chime in :))–
Ted Macklin/'85 XJ6SIII
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In reply to a message from TMack sent Sun 30 Aug 2015:

I was about to reply to your PM when I saw you had posted on
the forum Ted.
Most parts are still available in the UK for the Lucas
A133 range of alternators, so if you’ve still got it and the
stator and Rotor windings are good I’d suggest your cheapest
option would be to overhaul that unit. The only caveat is
that the slip rings need to be taken off to replace the SRE
bearing, and will need skimming on a lathe irrespective of
if the old ones are refitted or you fit new ones.
If it has been fitted for fifteen years it may just need a
set of brushes and a bit of fresh grease in the bearings…

You seeem to have some sort of fixation on regulators.
Generally speaking they either work or they don’t. Under
normal circumstances the regulator won’t make any difference
to the low speed output or voltage from the alternator. It’s
only when the output voltage from the alt gets up to about
14v that it starts thinking ‘‘I should be doing something
here’’. Up to that point it should supply the rotor windings
with either all they need or all the field diodes can give.

The main advantage of a high output alternator to us XJ
owners is the ability to give a decent output at a fairly
low engine speed. Because all alternators are designed to
work within about the same speed range it follows that the
higher the designed max output the higher the output at
lower speeds. That would explain why you are finding the
output of a 45 amp machine so disappointing when compared to
your 75 amp A133.
Having said that, have you checked that all is well with
your wiring? The usual suspect on the XJ is the wiring from
the alternator to the bulkhead connection, which is easily
checked by loading up the alternator to it’s max output
after connecting your DVM positive to the alt positive, DVM
negative to battery positive. Any voltage shown is voltage
drop on that circuit. In a perfect world there wouldn’t be
any.–
Dave Collishaw '79 Daimler Sovereign '56 BSA A10
Cambridgeshire, United Kingdom
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In reply to a message from sparx sent Sun 30 Aug 2015:

Thanks for the response Dave. It is with great interest that
I read the regulator does no work until voltage rises to
14.2v… so, undercharging can’t be the fault of the
regulator (now in pieces on my work bench). Hmm. OK.
I did finally locate the Transpo IL 219 regulator at
Alternator & Starter Parts Wholesale for $12.64. I’ve
cleaned the copper surfaces (slip rings) that the brushes
ride upon. In a perfect world they do need to be turned down
on a lathe I reckon; the inner most copper ‘‘ring’’ is just a
hair grooved out in the center. You can feel it with your
finger nail; not quite visible to the naked eye. Nobody here
in ATL will rebuild alternators; they only want to sell new
ones. Brushes have plenty of length remaining… I will be
taking it to AutoZone for free testing before re-installing
it, once the Transpo regulator arrives.

The particulars of when I could see 45 amps on the Bosch
ever so briefly, was if I let the engine idle with all
accessories turned on for a minute or so, which was causing
the battery voltage to slowly drop to 12.2 volts. Suddenly
raising the engine RPMs would jump the Alternator output to
45amps, again, ever so briefly. Settling down quickly 25 or
30 amps until the battery caught its wind. Then to about
8-10amps with no accessories. Battery Voltage would ever so
slowly rise to 14.15v, again, with no accessories. So,
apparently, that regulator is working as it should be…
This spare Bosch reman Alternator had been in my parts bin
for 5 years, so no doubt, I would have done well to polish
up the slip rings. Let’s see if some driving improves the
wimpy, at idle, charge capabilities under accy load… Oh
and I did notice the Alt belt was not in great shape. Ugh,
it takes all the abuse from oil leaks and what not and of
course is the innermost belt - making it a true PITA to
replace. I might not be using an OE Alternator belt this
time around…–
The original message included these comments:

Most parts are still available in the UK for the Lucas
A133 range of alternators, so if you’ve still got it and the
stator and Rotor windings are good I’d suggest your cheapest


Ted Macklin/'85 XJ6SIII
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In reply to a message from TMack sent Sun 30 Aug 2015:

OK, so the new Transpo IL219 regulator arrived. I Installed
it in the A133-75 that was so long lived, after its rebuild
20 years ago or so. Much to my disappointment, The
performance is equal to the lame Bosch rebuild I’d just had
in there temporarily. In fact it might be a bit weaker as I
can’t seem to coax 14.2v out of it no matter what I do. The
best I can muster is 14.05V. and yes, it too will deliver
about 47 amps under just the right conditions - just as the
Bosch reman would. So, maybe I am dreaming but I distinctly
remember in days of yor, the alternator being able to hold
14.2V at idle, with some accessories running.
For grins, I opened up the Bosch reman. The brushes were Not
centered on the slip rings. Ugh. and there was yet another
variant on the regulator - a Mobiletron VR-LC200. If, what
Sparx says it correct about regulators doing no work until
14.2 volts is reached, then I am going to have to remove the
diodes and load test them this time around. I’ve got new
slip rings on order for grins and I’m going to double check
my windings.
Someone posted here awhile back that he purchased the OEM
Jaguar regulator for about $130 and gets 14.2v at idle
consistently. That said, I am suspicious about these Chinese
regulators, for the one I dissected had only one transistor,
one diode for surge protection and one zener, plus some
resistors. This is not consistent with the schematics found
on Google search which all show two transistors…–
The original message included these comments:

My ~20 year old, rebuilt A133-75 finally failed about 5
years ago. A breaker yard spare went in. While it never
topped the volt meter scale to the exact point of the
previous one, it did manage to keep a full charge until last


Ted Macklin/'85 XJ6SIII
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In reply to a message from TMack sent Sat 5 Sep 2015:

Ted:

Electrics are always challenging
to me.

My son says that Chinese electrics
are built to a price. Just enough
to get by. You seem to have seen it,
as well.

All that being said. Twenty years of
service.

Battery stays up.

Not all that bad.

So, is a missing 15v all that important?

The dash guage on my car doesn’t get into
the 13v range. But, everything is working
quite nicely. I recognize it’s foibles,
But, no reason for me to break out my patch
cord and use my HF VOM to track alternator
performance. It’s 140 amp GM Delco seems to
be doing it’s task.

So far, the new Malaysian built starter
cranks just fine. Toes and fingers crossed!!!

Wax and polish in progress. Running great,
need to get looks up to par.

Carl–
The original message included these comments:

20 years ago or so. Much to my disappointment, The
performance is equal to the lame Bosch rebuild I’d just had
in there temporarily. In fact it might be a bit weaker as I
can’t seem to coax 14.2v out of it no matter what I do. The
best I can muster is 14.05V. and yes, it too will deliver
about 47 amps under just the right conditions - just as the
Bosch reman would. So, maybe I am dreaming but I distinctly
remember in days of yor, the alternator being able to hold
14.2V at idle, with some accessories running.
consistently. That said, I am suspicious about these Chinese
regulators, for the one I dissected had only one transistor,


Carl Hutchins 1983 Jaguar XJ6 with LT1 and 1994 Jeep Grand
Walnut Creek, California, United States
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In reply to a message from TMack sent Sat 5 Sep 2015:

I’m wondering if you’re getting obsessed about a ‘‘fault’’
that doesn’t exist Ted.
The ‘‘on car’’ test for regulator regulating voltage is to
have a fully charged battery that will draw no more than
about five amps at 14.2v, with no excessive loads switched
on, and sufficient revs on the engine to ensure that the
unregulated output of the alternator would be in excess of
the current draw from the battery and any loads on the car.
If you satisfy these criteria and are only showing 14.05
at the battery check what you are getting at the alternator.
Back in the days when I would be stood at a bench
reconditioning alternators we would do what we called a
‘‘static test’’ on the regulator. It involved hooking it up
with a variable voltage supply on the field diodes
connection with a dummy load replacing the rotor windings.
The voltage would be increased until the regulator switched
off, then reduced until it switched back on. I don’t recall
the exact range within which the regulator passed this test,
but it was a very narrow band around the 14.2v region.
Battery technology has moved on a bit since then, the
voltage is slightly higher.
The electronics inside a regulator are fairly basic, I
could knock off a working circuit diagram without breaking
into a sweat. As you suggest, usually just a couple of
transistors, one for output which is switched off by another
at the appropriate voltage, plus a few bits and bobs for
protection from the field winding back-EMF. I would expect
to see an IC somewhwere in there these days. Maybe you have
one on the board but it’s so small you’ve missed it?–
Dave Collishaw '79 Daimler Sovereign '56 BSA A10
Cambridgeshire, United Kingdom
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In reply to a message from cadjag sent Sun 6 Sep 2015:

For grins, I checked the voltage drop across the wiring
harness - from the Battery B+ over the same connection on
the Alternator. 0.2volts drop with every accessory running
at full tilt. Also, I got rid of all spade connectors at the
Alternator years ago - everything’s bolted up now. Given
tolerances in manufacturing, I guess I should be satisfied
with 14.05Volts (as opposed to 14.2) at the Alternator, at
idle, with no accessories running. But the mystery to me is
why it can’t hold close to 14v with minimal accessories
running? steadily declining as each accessory is turned on,
until it dips below the red mark on the dash gauge (at
idle). About 12.2 volts on my Fluke.
And why is the max output only 47 amps when the alternator
is rated at 75 amps? Yes indeed Carl, electrics can be
challenging, especially if perfection is the goal (as the
case here).
Pity I can’t easily monitor the voltage and the current at
the brushes as I’m betting this would tell the secret. Or
perhaps figure out a way to bench test the regulator…
Just For the Heck of it, I ‘scoped out my 2002 Grand
Marquis’ Alternator’s behavior pattern as reference. The
voltage varies only a fraction from 14.5 no matter the load
or engine RPM. And oddly the amperage seems locked at 27
amps when fully loaded with all accessories. Settling to 8
amps or so with no accy on. But then I’ve read that these
modern Alternators are controlled by the ECU. No wonder I’ve
never had to even think about it in 200K miles /15 years -
everything’s managed to the hilt.–
The original message included these comments:

Electrics are always challenging
to me.


Ted Macklin/'85 XJ6SIII
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In reply to a message from TMack sent Sun 6 Sep 2015:

To get the absolute max output from the alternator either on
the test bench or on the car we invariably had to load the
battery with a carbon pile either fitted to the test bench
or on our portable battery tester.
If your battery is being charged at, for example, ten
amps, the important thing is that with all the loads
switched on it’s still charged at about ten amps, assuming
the total load (battery and consumers) isn’t in excess of
the alternator max output and the alternator is running at a
speed that it can deliver that output.
If the battery resistance is such that it’s only drawing
10 amps, and the loads are 20 amps, that’s going to stay the
same irrespective of the max output of the alternator, so a
75 amp alt is going to supply 30 amps, exactly the same as a
40 or 50 amp alternator, the only difference being that a
higher output alternator will tend to deliver that 30 amps
at a slightly lower pulley speed.
I wouldn’t expect for one minute to see the alternator
covering all the vehicle loads at tick-over (idling) speed,
so given that situation it’s not unreasonable to see the
battery voltage drop. The battery is supplying the
difference between what the alternator can deliver at that
pulley speed and what the loads are drawing, so it’s voltage
is inevitably going to gradually fall.
The voltage on your 2002 car demonstrates a point I
mentioned, modern batteries start ‘‘gassing’’ at a higher
voltage than they did just a few short years ago due to
improved plate technology, so modern regulators allow the
voltage to go slightly higher to take advantage of that.–
Dave Collishaw '79 Daimler Sovereign '56 BSA A10
Cambridgeshire, United Kingdom
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In reply to a message from TMack sent Sat 5 Sep 2015:

Hi Ted and Listers,

I haven’t been active for a while now and was just reading
about your alternator woes. I experienced similar voltage
dives at idle with my 83 XJ6 (lights dimming, fans slowing,
etc. and having to shift to neutral at stops and rev the
engine to bring the charge up). Did voltage drop tests on
all pos. and neg. connections, cleaned and greased them.
The ground strap connection from the frame to bell housing
was particularly bad, but still not a satisfactory
improvement. Since then, I changed to a Delco CS 130I 105
amp iceberg alternator, mounted up top in place of the air
pump with a small v belt pulley. No voltage drops at all
now. Of course I have some different Jag challenges now that
I may be posting about. Happy Labor Day and good to be
back.–
Bud
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In reply to a message from Jaguarbud1 sent Mon 7 Sep 2015:

Great hearing from you again Bud!–
The original message included these comments:

Hi Ted and Listers,
I haven’t been active for a while now and was just reading
about your alternator woes. I experienced similar voltage
dives at idle with my 83 XJ6 (lights dimming, fans slowing,
etc. and having to shift to neutral at stops and rev the
engine to bring the charge up). Did voltage drop tests on
I may be posting about. Happy Labor Day and good to be
back.


Ted Macklin/'85 XJ6SIII
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In reply to a message from sparx sent Sun 6 Sep 2015:

Last night, through much determination and perseverance, I
hacked into the sick Lucas 15TR regulator. It’s the only one
potted inside a block of epoxy. Lo and behold, it does have
the two transistor layout, one of which is an actual TO-220
Power Transistor and a smaller TO-92 Transistor; the TO-220,
had its heat sink riveted to the 15TR’s thick metal surround
case, as if to say they cared about it’s ability to handle
some current. (unlike the minimalist designed Chinese
knockoffs with their tiny transistor, a single SMT (surface
mount technology) with little or no heatsinking)…

I’ve read that the field winding doesn’t need much current
so my theory is that the Chinese knockoffs will work, if
only barely. Conversely, if you want to realize the true
capabilities of the Alternator, ie the ability to deliver 75
amps and hold 14.2 volts at idle with some accessories,
you’ll need the Lucas 15TR or better yet, a hand selected
Jaguar version of it. Sadly, the Lucas 15TR is nearly
unobtanium State-side; would be NOS now anyways, I reckon.
(Was I supposed to know they went belly-up awhile back??)
Ugh. The smart one was the guy here, who posted awhile back
that he, in the end, decided upon the Jaguar regulator -
even at quintuple the price. OMG.

Oh and one more thing, those slip rings are not solid copper
(as I’d thought). The copper is actually only a little over
a mm thick, so if they are grooved out, don’t bother
skimming them, as you’ll be down to the plastic core, sooner
rather than later.–
The original message included these comments:

could knock off a working circuit diagram without breaking
into a sweat. As you suggest, usually just a couple of
transistors, one for output which is switched off by another
at the appropriate voltage, plus a few bits and bobs for
protection from the field winding back-EMF. I would expect
to see an IC somewhwere in there these days. Maybe you have
one on the board but it’s so small you’ve missed it?


Ted Macklin/'85 XJ6SIII
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In reply to a message from TMack sent Sat 5 Sep 2015:

Hi Ted and Listers,

I haven’t been active for a while now and was just reading
about your alternator woes. I experienced similar voltage
dives at idle with my 83 XJ6 (lights dimming, fans slowing,
etc. and having to shift to neutral at stops and rev the
engine to bring the charge up).

It’s perfectly normal for the voltage to drop in situations mentioned,
Bud…

…with the usual alternator set-up; at such low revs the output is
generally insufficient to counter high current drains. This is because
alternators has a top rev limit before they disintegrate - and the pulley
dimensions guard against it, at the cost of low idle alt output.

As the temporary loss of charge voltage in idle is of no consequence - there
is nothing alarming in this. As the lack of voltage may also be ascribed to
a bad battery, some judicious evaluation is required before just upping the
alternator.

Of course, upping the alt is not ‘wrong’, but while using a smaller alt
pulley will certainly increase idle output - you should carefully check the
max permitted rpms on the alternator fitted. And ensure that the limit is
not exceeded at relevant engine rpms. In fact - a smaller pulley on the
original alternator would eliminate the symptoms described - with the same
inherent danger…

As a matter of interest; what is the ratio between the two pulleys you are
using…?

Frank
xj6 85 Sov Europe (UK/NZ)

Did voltage drop tests on
all pos. and neg. connections, cleaned and greased them.
The ground strap connection from the frame to bell housing
was particularly bad, but still not a satisfactory
improvement. Since then, I changed to a Delco CS 130I 105
amp iceberg alternator, mounted up top in place of the air
pump with a small v belt pulley. No voltage drops at all
now. Of course I have some different Jag challenges now that
I may be posting about. Happy Labor Day and good to be
back.-----Original Message-----
From: Jaguarbud1
Sent: Tuesday, September 08, 2015 1:43 AM
To: xj@jag-lovers.org
Subject: Re: [xj] more A133-75 alternator observations and challenges

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In reply to a message from TMack sent Sat 5 Sep 2015:

Thanks for the info Frank. Frank wrote:

‘‘As a matter of interest; what is the ratio between the two
pulleys you are using�?’’

Frank
xj6 85 Sov Europe (UK/NZ)

I’m using a 2.5’’ pulley on the alternator now and I have it
running off of the crank pulley. Not being sure of the
crank diameter, I can’t calculate the ratio right now. I
originally ran it off of the water pump pulley without much
improvement at all. I’m too old now for high revs (which
begs the question ‘‘What is the alternator burn out danger
point?’’), so I’ll keep my revs on the safe side.–
Bud
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In reply to a message from TMack sent Sat 5 Sep 2015:

Thanks for the info Frank. Frank wrote:

‘‘As a matter of interest; what is the ratio between the two
pulleys you are using…?’’

Frank
xj6 85 Sov Europe (UK/NZ)

I’m using a 2.5’’ pulley on the alternator now and I have it
running off of the crank pulley. Not being sure of the
crank diameter, I can’t calculate the ratio right now. I
originally ran it off of the water pump pulley without much
improvement at all. I’m too old now for high revs (which
begs the question ‘‘What is the alternator burn out danger
point?’’), so I’ll keep my revs on the safe side.

That’s fair to fine, Bud…:slight_smile:

It was just a general warning about altering alt pulley ratios to increase
low charging at low idle - which is ‘normal’ and harmless. I ‘think’ the
disintegration point of alternators is somewhere beyond 8000 rpms

Frank
xj6 85 Sov Europe (UK/NZ)-----Original Message-----
From: Jaguarbud1
Sent: Wednesday, September 09, 2015 9:52 AM
To: xj@jag-lovers.org
Subject: Re: [xj] more A133-75 alternator observations and challenges

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In reply to a message from Frank sent Wed 9 Sep 2015:

Fresh alternator found at breaker yard… The engine had
only 39K on the odometer. Not labeled as a Lucas alternator
per se… but inside was a TR 15 regulator. And the pulley
was smaller - requiring an inch of travel on the adjusting
screw. Hmmm. Once installed, turns out, it was not the Holy
Grail I was expecting. Yes, it does hold 14v with high beams
on, but with A/C on high at idle, in ‘‘D’’, the voltage drops
to 12.2. :frowning:

So I guess I was dreaming that I recall 14.2v holding, no
matter what the load conditions.

Oh btw, DIY alternator regulator builders have abandoned old
school transistors for MOSFET designs which produce little
or no heat. Perhaps an SMT MOSFET is what I’ve seen inside
the Chinese mfg substitute for the Lucas TR 15??

The only option now, beyond a DIY regulator, is the Jaguar
regulator. ONly one left in the country. and it’s $90.00.
I’m not feeling that spendy right now…–
The original message included these comments:

‘‘As a matter of interest; what is the ratio between the two
pulleys you are using…?’’


Ted Macklin/'85 XJ6SIII
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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I recently purchased one of those wireless VA monitors off of ebay (~$45ish). It uses a Hall motor around the Alternator B+ wire to monitor the current charge rate. Interestingly, the alternator does produce about 50 amps when loaded up with accessories at idle. For grins I discharged the battery for about 3 minutes then cranked with all accessories fully drawing, but this time I raised the idle to about 1200 RPMs - I briefly saw 65amps at about 13.1V. Oh and FYI max Alternator voltage was 13.9 for no load at full battery charge. So, I’m pretty satisfied with the Atl current provided. Just wishing I could get 14.2V out of the Alternator, no load. Fixing to dive into that small exciter wire at back of the Alternator. Chasing it back to where ever, to find out if it’s working properly. Stay tuned.

**
Alternators are like batteries, Ted - they drop voltage under load…

Part of the load equation relates to battery state - a discharged/defective battery draws lot of current, and the alternator responds by a drop in its voltage. As the battery, at rest, is seldom stays at much more than some 13,6V - the battery voltage versus alternator regulated voltage reflects the current actually delivered by the alternator…

Basically; the alternator only needs to deliver enough current to match current load. The alternator specs describes what the alternator can do - not what it does at any one time…

Ie, for current to flow - the current must have somewhere to go…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
**

On my crude bench test set up, using a Dewalt drill to spin it up, I was amazed at how little voltage was required to excite the armature windings… (used a small 12v test light as current limiter). But what I don’t know is what effect that a given small voltage at the exciter has on the ALT output. FWIW, I have seen, in the parade of alternators on my car, some that will produce 14.2v with accessories off, engine at idle. (The gauge sat right atop 13V). Oh and I did accomplish one very tedious but satisfying job yesterday - cleaned all surfaces of the battery ground strap along with associated bolts and washers. Not that it was in bad shape mind you, but I did gain back .1V :slight_smile: Also as I had to access the ALT B+ wire at the bulkhead (in order to slide the Hall Motor over it), I cleaned up all those mating surfaces as well :slight_smile:

**
Basically, the alternators are generally self-exciting due to remanent magnetism, Ted - the exciter voltage is supposedly just a start-up help…

The output voltage of different types may relate to the regulator fitted - or imperfections? Or relates to battery state or other external factors - a low battery draws higher currents than a fully charged one. 14,2 V is not necessarily an industrial standard, and as long as the alternator delivers voltage above the nominal 12,8V of lead/acid batteries it will charge…sort of…

Frank
xj6 85 Sov Europe (UK/NZ)
**

I haven’t read this entire thread. I would like to point out, though, that on the V12 we’ve discovered that many frustrating symptoms on the alternator eventually were found to be caused by a failed crank damper. On the V12, the alternator belt is driven off the OD of the damper. When the rubber in the damper fails, the outer ring can slip, resulting in the alternator looking like it’s turning as it should when in fact it’s turning far more slowly and hence not putting out the power it should. In some cases it squeals, but not all.