Replacement alternator for Morph arrived today.
This one has the same connector (where the three leads go in) but also has two additional stumps which didn't feature on the old unit.
They are marked B+ and W. I'd guess one is for a rev counter but can any one provide a definative answer please as to what they are for. May be a chance for some additional developement :-)
Lee D
W is the feed to the alternator, B+ is, I "think", the voltage sensing feed for internal regulation. it turns it into an external sensed regulator, for use with the older blocking-diode type of split charge systems. Badger.
Badger uttered summat worrerz funny about:
Ah , me thinks I need to know more. Although Morph only has the three wires in the one block (or would have if there were a block - presently they are individual items IYSWIM) , he also has a big diode pack which looks like a coil for the split charge system. I have ignored this until now but curiosity has now got the better of me. Morph has 2 Batteries, one I understand purely to fire the starter and the tuther for auxillaries.. though I'm sure it's more complexed than my basic understanding.
Lee
Lee - do you have the army manual for the ambulance with the wiring diagram showing the split charge diodes etc.? 4.7 Mb pdf file here if not. I could extract some relevant bits
It's been on the web but I can't remember where.
Slip of the keyboard, I'm sure you meant W for Tacho.
Little B+ will be the sensing lead for a battery-sensed alternator. You'll have to connect it as otherwise your alternator will have no output regulation. The alternator does not default to a machine-sensed unit if the connection is not made.
You probably ought to identify this alternator properly to be 100 percent sure.
Indeed I did, thanks for correcting my slippage!
I've seen Lucas (A133?) alternators where the B+ (small terminal) is connected internally and requires no external connection, but can be used for external sensing by disconnecting a link wire internally!
Sounds as if it might be a 22ACR, some of them had the multiple terminals I think?
Badger.
doesnt the diode pack work in the same way as a simple split charge relay would? My ambi came with the split charge running off a relay switched by the charge light and all the wiring to it looked stock? (i.e. crappy!)
That's useful. I presume that the internal connection is there by default and to make it 'unsafe' you need to go inside.
Blimmey, this is getting complicated. The alternator was provided to replace what looked like an A133 on an exchange basis yet this one doesn't have all the black plastic at the back and is much shorter as a result.
Is it just a case of wiring up the wires I have , kick up and check the output voltage and if it goes above say 14.5 then begin to ponder further?
Lee D
Lee_D uttered summat worrerz funny about:
Right, gone and fetched it off the Kitchen window sill,
It's by CJF Rotating electrics and say REP Lucas A463.
The W terminal has a black plastic cap on.
The B+ terminal doesn't , The B+ also appears to have a male spade connector on the same pole too.
Why is nothing ever simple!
Lee D
C J F ROTATING AUTO ELECTRICS LTD UNIT 6-9 GREEN INDSTL EST STATION RD CANNOCK STAFFORDSHIRE WS12 4EG
01543 424 717Give them a ring and find out exactly what the score is.
PS - the post code given may be wrong
Dougal uttered summat worrerz funny about:
TA!
Lee D
Lee_D uttered summat worrerz funny about:
Sorted,
Nice chaps too! Big ones of the three in the plug go to +, smaller spade goes to ignition light
B+ can be left empty and also the W, that'll do for a start.
Rev counters - I take it the simplest option is still to go for a feed from the coil "-" unless I fit a 1990 circa Classic dashboard at some point. I.e. do the rev counters that run from the alternator need some extra gizmology to work out the pulse or are they essentially the same?
Lee D
One of the simplest tuning tricks I did with my classic was to fit an alternator with a slightly smaller pulley.
Suddenly the engine would rev about 500RPM higher at the top end.
Strangely no change in speedo though. (!)
Moral - Must be some clever matching in the instrument panel to allow for ratio between crankshaft and alternator pulleys.
David
It doesn't matter which alternator you have if you use the Classic dash, just solder a wire on to one end of any of the stator wires where they go to the diodes to pick up an a/c signal and connect to rev counter trigger wire (white). You may have to change the pulley size to match the rev counter to the engine speed.
Martin
On or around Tue, 29 Aug 2006 18:09:34 +0100, "Lee_D" enlightened us thusly:
if it has the 3-blade connector with 2 fat ones and a skinny one, then that's all you need to connect if you have the 3-wire plug. The 2 fat ones are output and the skinny one is fed from the ignition light via a brown/yellow on most things but possibly not on a 101.
The W terminal can be used to feed a rev counter or other devices - I've seen it used to heat an electrically-heated auto-choke.
B+ is probably output. I forget right now... hmmm. I should have one outside to look at, 'ang on...
yeah, B+ is output. It'll be so that it can be connected to the kind of thing that has a ring terminal on the output wire.
some of them have a D+ as well, which is the same as the small terminal of the 3-blade block.
a quick prod with a continuity tester should confirm that B+ and either of the big blades are connected.
The W terminal puts out AC which is why people run rev counters from it, although it's prone to some impressive inaccuracies.
On or around Wed, 30 Aug 2006 11:11:29 GMT, rads enlightened us thusly:
not really, I think they rely on luck. I replaced the alternator on our TDi with the same model, same pulley, and it read about 1000 rpm high at top-end revs, or about 500 rpm high in the middle.
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