At 5m rpm the readings that I'm getting from the three wires from the stator are: two at 71 volts and one at 61 volts. I understand that all three should be equal. Is that 10v difference within tolerance? Or is my stator caca? Obviously, I'm having battery charging issues. Any help would be appreciated. Thanx.
Thanks for responding John, but my querstion is...is the 10v difference acceptable, or has the stator gone south? I've gone thru all the other tests, and I have searched all the threads I can find in T595net. I swapped the reg/rectifier, done the fuses, checked continuity, etc...I'm down to the stator or a blown connector somewhere...I don't think that it's a relay issue...yet! But I would like to get confirmation on the stator!
It won't measure right if you disconnect it from the regulator. That would also explain the small difference in output from the three windings, and also probably indicates the alternator is working fine.
Can you measure it when its connected and running?
If you have fully disconnected the stator to take those readings then the whole stator should be floating relative to the rest of the bike.
The fact that the voltages are stable is worying and the 10 volts difference is interisting.
I suspect that you have a short to ground on one of the windings.
Make the measurements I suggested in my first post.
If you have a resistance to ground from any of the 3 wires that is less than tens of meg ohms then the stator is in need of a rewind.
Idealy you should not be able to get a groung resistance reading with a normal DVM, it should show up as over range (open circuit)
Thanx for joining in. With the alternator disconnected, I'm getting 61v from one wire and 71 from other two at 5,000 rpm. (again, I have read that they should be equal) If I check the charging voltage at battery (starting with an indicated 12.8v battery charge at rest) I'm reading 12.4 at idle and moving up to 12.7 reving motor to 5-7thou rpm...obviously not getting the ideal 13.5 - 14.7v.
I have checked continuity from first connector (under tank) to the second up near the reg/rectifier.
I have visually checked the fuses and switched the two 30A ones just in case.
The battery was replaced 1 month ago as I felt the original factory job was starting to crank weakly. The new battery held out for 3-4 weeks until it died. takes a charge and will run the bike for 3-4 days (8-10 starting cycles before it dies again)
With engine stopped and stator (alternator) disconnected, meter switched to Ohms, at lowest range, I get a consistent .5 reading from one lead to another on all 3 wires.
If I connect one lead to one of the three yellow wires and ground the other to engine casing I'm getting no reading on any of three wires.
I have switched reg/rectifier with another unit.
I haven't done anything with relays...don't know where or how to start.
While I was under the tank, I removed and serviced the air filter (K&N), changed Spark plugs, changed fuel filter (I have the metal couplings) generally cleaned up the grime and pulled apart all couplings sprayed with WD-40 and reconnected them.
I'm of the mind to swap out a stator and see if my problem is solved. It'll cost approx $150. for an aftermarket one from Canada. Why should I buy a genuine Triumph unit, the "Prince of Darkness" continues to curse Brit machinery!
Forgot to mention:
- No Alarm fitted
- No evident short...bike sits for 4-5 days...battery keeps charge.
you said :-
"If I connect one lead to one of the three yellow wires and ground the other to engine casing I'm getting no reading on any of three wires."
I presume that you mean over range - What range were you taking that reading on? Should be on the highest range - not still on the lowest.
" If I check the charging voltage at battery (starting with an indicated 12.8v battery charge at rest) I'm reading 12.4 at idle and moving up to 12.7 reving motor to 5-7thou rpm...obviously not getting the ideal 13.5 - 14.7v."
That's very like the numbers I was seeing with my stator short to ground. Your system is producing some output, but not anything like it should.
When you swapped the reg/rect unit did you check the running voltage?
Got to admit I still suspect the stator but that's probably just because that's what died on mine - I think Rigsy had trouble with his rectifier.
Before you spend money on a new stator to test by substitution it is worth pulling the existing unit for a visual examination. When mine died the burned insulation on one of the 18 coils was clearly visible.
Quote: With the alternator disconnected, I'm getting 61v from one wire and 71 from other two at 5,000 rpm. (again, I have read that they should be equal)
I'm a bit confused.
You cannot measure each output to ground as you will get a meaningless reading if the alternator is disconnected as its is "floating" ie the 0v (chassis) is not related to the voltage generated. (Hope I'm making sense)
You have to measure between the windings. On the 3 pin plug measure across any 2! This will (probably) give you a more meaningful measurement.
Quote: If I check the charging voltage at battery (starting with an indicated 12.8v battery charge at rest) I'm reading 12.4 at idle and moving up to 12.7 reving motor to 5-7thou rpm...obviously not getting the ideal 13.5 - 14.7v.
You've checked the DC performance of the Alternator and its checked out OK.
You also mention that you swapped out the rectifier, and changed the battery without fixing the problem.
Mmm The mystery deepens.....
As John said, The most likely culprit is the stator failing under load. The Triumph system is a bit basic so the alternator deliveres full load all the time. What is not needed is dissipated in the regulator / rectifier as heat.
Just put your hand on the rectifier when the bikes running.
Truth be said most systems are like this.
The Generator will output 3phase AC voltage proportional to the engine speed (Basic Physics relative to Magnet strength and No of windings intersected by the magnetic field)
This is then changed to "Variable" DC with a 3-phase rectifier before being regulated to 13-14V with the Regulator (Zener Diode)
Riggsy is definately right about the crankshaft alternators.
Not sure about the earlier external type alternators.
The regulator on those sits inside the end cap of the alternator housing and seems to have rather small surface area for cooling.
That said the regulator is right up against the alternator's built in cooling fan and it is probably there to allow it to dump all the excess energy.
riggsy: Basic Physics relative to Magnet strength and No of windings intersected by the magnetic field
I thought that was true for a Dynamo ... but in the case of a Alternator the magnet is a coil with a variable voltage pumped through it to vary the magnetic field (regulation)
the reason there is a difference in v out with revs being, at low revs the regulator is set to "100%" but there just isn't enough field to give you your 14.x volts ... when you hit a certain rpm it actually starts regulating from there up to the limiter by reducing the v to the coil...
or are the Daytona electric not that sophisticated?
I got round to checking the Haynes manual (for pre-'02 type FI engines, with alternator mounted behind crank).
These alternators use a DC field winding in the rotor, powered from the battery. The regulator controls the field winding current to create the necessary magnetic field strength, to generate the desired voltage at the alternator output, in 3-phase AC. This also varies the load placed on the engine and prevents overcharging.
The regulator probably also has a zener/resistor arrangement for final regulation hence gets a bit hot. The rectifier (6-diode bridge) converts the 3-phase AC to DC. Both integrated in a single unit.
Its worth checking the brushes are not worn or dirty. The brushes connect the regulator to the DC rotor windings via a pair of slip rings in one end of the alternator. They are the least reliable part of the alternator.
Only thing I'm not sure about is if the newer engines ('02 onwards) operate the same way. But I'd be surprised if they didn't because this would represent a backward step and would certainly be a far inferior system.
Crankshaft alternators on the later bikes are rotating perminent magnet type.
The only difference between the Alt on my '03 bike and the ones Triumph used from the sixtys to the eighties is that the rotating magnets go round the outside of the stator on the modern ones.
It is very basic and if it is put together right it should be very reliable.
No bearings of it's own and no brushes to wear.
If the crank shaft nut is done up right, the stator is bolted in properly (mine had one loose screw but hadn't moved) and the insulation doesn't break down (mine did) there is nothing else to go wrong.
It is possible to shut off the alternator when the output gets too high. That type of regulator saves a bit of energy and runs cooler.
A retired electronics engineer I know designed and built such a unit for his 3TA restoration. The voltage controler sits in a box the size of a matchbox and stays cool unlike the zenner it replaces, but it is much more complicated.
Here's a basic thought (I'm not super good with electrics, mind):
Have you had a peek at the resistance through the regulator? My thought is that if the resistance is too high across it, it won't allow enough voltage to return to the battery. I don't know what the correct ohms should be, but I'd guess it'd be between 1-2 M-ohms...just making a stab here.
Ok Guys...I cracked the case and removed said stator (the magnetic pull on the casing is wierd...felt as if some retaining spring was connected and I went back to the manual to make sure) visual inspection looks ok except for black stained winding at point that the three wires lead off. Anyway, its off to RM Stator Inc. in Quebec Canada. They will test it and get back to me. I'm praying that it's bad! If faulty, they will rewind it for U.S. 150. Shoud take 10 days to two weeks...will report any findings.
Stator back from RM Stator in Canada. They provided me a new stator with my original wires and coupling, ready to plug in for U.S. $155. And they work fast. I highly recommend them. Check them out: >http://www.rmstator.com/ Bike is running fine, battery charging at 14+ volts. All's well. Thanx for all the help and advice! Nos vemos, Peter
My output voltage seems to vary from being 'normal' (increasing over 14V when throttle up) to sitting at just about battery voltage; also sometimes seems to be behaving normally with throttle up, other times, actually seems to be dropping with revs!
This is what my stator looks like - the difference in colour of the windings is very apparent - do they normally look like this or are the dark ones baked?
Edit Ok looks like I found the problem: Measuring ac volts between each pair of phases gives ~ 25V at idle when disconnected from the regulator; When connected to regulator, the three phases individually now measure ~ 7.2, 7.8 & 0.7 V to ground (also noticed wires getting hot to point of almost melting insulation - the connector plug too hot to touch!) Of course there should be no reference to ground at all, only between phases.
Disconnected the regulator & measured resistance of each pin of regulator input to ground - et voila, one is short to ground (same pin that measures the 0.7V ac to ground)
So looks like a new regulator definitely required. Now the other question is - have I cooked my stator beyond danger level? It seems to be OK other than the discolouration (which was probably from the heat of the excess current through that phase) yet appears to be OK at least off-load - I guess I can start with the regulator & then get the stator later if I find it breaks down under load.
Both are available aftermarket from Electrosport (who incidentally make the stator kit that RM Stator referenced above sells);
I also found that RM price on EBay for the stator at $139 is actually $20 less than their website price ($159 plus whatever shipping is) but there is also another EBay vendor who sells the same Electrosport stator for $5 less still at $135, but also another $5 less on shipping, so $141 total shipped vs $151 from RM on EBay
My buddies Tiger smoked it's stator a few years back. Well, just lately it started melting the plug to the rectifier. He installed crimp on plugs to the stator wires, but the remaining plug on the rectifier once again got quite hot. We followed the guidlines above and found that no stator leads went to ground, all stator leads had continuity between themselves and none of the rectifier leads went to ground either.
We cut all the leads, put new connectors on them and fired the bike up. All the leads (connected w/ bike at idle) measured around 5.7 (meter on dc) to ground. The new leads didn't get hot immediatly which my buddy told me it did the time before.
Problem solved? Seems like it. We didn't mind which stator lead went to which rectifier lead; we figured if it mattered, they would be color coded. Oh, the battery never lost charge, the only symptom was the hot plug.
Took mine for a service at Boyers last week, and mentioned the charging problem I have also had. They advised me to buy an upgraded cable from the alt to the reg. Appears the cables running through the loom get too hot and break down(They are 1mm). The new cable (2.5mm)can be installed without major hassle, and then just cut the connectors off the old cables.
New cable is called Alternator fly lead
Part Number T2504111
Well - I installed it & went to start but the motor would barely turn over; thinking it maybe wasn't aligned properly for some reason I removed it, checked all the screws (strangely one seemed galled a little and loose) So I re-assembled, made sure it was alinged properly on the locating boss & tried again - same result. It was like the battery was really flat - would be trying to turn over but not managing to spin it at any speed. However the battery was good - lights were bright & volts stayed up over 12.5 even with lights on. The volts sank however when the starter button pressed: I then realized something was jamming.
So I loosened up all the alternator cover bolts & just tried a couple of quick cranks (without starting) This time it would turn the engine.
So I removed the alternator cover again - this time the bolts holding the stator were completely chewed up and loose. Lots of metal shavings on the rotor. It's obvious from the condition of the screws that stator is sitting too deep in the housing and contacting the rotor. I measure the thickness of the stator center housing - it is a good 3mm thicker than the OEM (OEM is about 21mm - this is more like 24) Hence TOO thick to fit in the housing without the bolts jamming on the inside of the stator. Another difference in the dimension is this measures 102mm across outside of adjacent coils; OEM is 115mm.
This could have done a lot more damage than it did - as is, the screws came off worst (they're ruined & will need to be replaced) The problem of being too thick could not possibly have been identified as it was being installed (you can't see blind inside the cover of course) without measuring it first. I had no reason to suspect this would be too thick as it was "supposed" to be the correct application so why would I measure it? 1mm smaller would have been even more disastrous - still too thick but would have possibly allowed engine to start. This would have resulted in the rotor being damaged and potentially a bunch of metal fragments getting into my motor.
I'm waiting to see what first the vendor & secondly Electrosport have to say about it.
What happens when the regulator goes short is that the stator is feeding max current into short circuit & fries it.
I was hoping for respite, but based on the visual (see above) & circumstance of the short, no such luck.
Electrosport identified another stator to match my OEM & shipping it - so we'll see whathappens next.