Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
Alternator Reliability Poll
- Thread starter alpinelakespilot2000
- Start date
BillL
Well Known Member
Sad but currently true. Read the aeroelectric site about the development of the B&C alternators. Auto alternators have a couple of issues for planes. One is no over voltage protection, but that is cured with an OV module from B&C. The other is that using the field wire to activate and shut off the alternator. Some, but not all, automotive will fail instantly if the field and load is removed, like shutting off the buss in flight. Bob did the testing on these in his lab. Again Aeroelectric has a protection for this that can be added to the auto alternators.
With those two things, one wonders if the auto might be just fine if either a remanufactured, or new one is used.
As a PP owner, I hope that HET will get their act together - fix the problem and offer a customer support program for premature field failures. Let's keep the pressure on them to do so.
Oh - the quality reman bosch 60A is over $200, a member in the autoparts business called the other rebuild as "Krylon Overhauls". Factory Remans (claiming new OEM bearings and lubricants) are available from ND too, if you go to their site.
Last edited:
Captain_John
Well Known Member
I wonder how the meetings at Hartzell's are going post acquisition?
I would think that this poll has come up in conversation!
CJ
I would think that this poll has come up in conversation!
CJ
bret
Well Known Member
Now I am interested in this thread but with a twist, the engine I bought came with a certified PP and remote regulator, which is on my sub panel, I wonder if some of theses failures, excluding stator wire breakage, but due to heat and vibration on the internal regulator? hung out there next to that big vibrating fan?
Bill.Peyton
Well Known Member
I stand corrected CJ only one VR failure and that occurred outside the 250 hour survey.
I just finished removing my PP and replacing it with a BC and regulator. I did get 500 good hours out of the PP, but didn't want to push my luck based upon the high failure rate of the PP product brought out by this survey. What a pain finding a place to mount the regulator under the panel of the -10 on the firewall. I almost got myself stuck upside down under the panel at one point. ��. Had to have a buddy help extract me
I just finished removing my PP and replacing it with a BC and regulator. I did get 500 good hours out of the PP, but didn't want to push my luck based upon the high failure rate of the PP product brought out by this survey. What a pain finding a place to mount the regulator under the panel of the -10 on the firewall. I almost got myself stuck upside down under the panel at one point. ��. Had to have a buddy help extract me
Last edited:
Captain_John
Well Known Member
Bill,
I was also wondering if that OP was using a Ford style regulator and not an LR3C.
When I am working under the panel I call it RV yoga!
Good choice converting over! The boredom is priceless!
CJ
I was also wondering if that OP was using a Ford style regulator and not an LR3C.
When I am working under the panel I call it RV yoga!
Good choice converting over! The boredom is priceless!
CJ
tc1234c
Well Known Member
I used a Canadian Aero 40 amp internally regulated Dennso alternator for 1,750 trouble free hours. When I replaced it with a PlanePower 60A unit 100 hrs ago, I found the mounting bracket cracked. Otherwise it still runs smoothly and charging.
O320 engine with fixed pitch prop.
O320 engine with fixed pitch prop.
donaziza
Well Known Member
About 470 hours on a PP, then failed. Replaced with a B&C. Now about 60 hours on it. Somebody, a few pages back said we should have a poll on starters. I have a Skytec. About a year and 1/2 ago, I started a thread on what looks like "black grease" on my starter. That set off a firestorm, as apparently a heck of a lot of other guys had the same problem. I "think" Skytec started replacing them, although I'm still cleaning my old one.
Just click on my avatar, and scroll. You'll find it.
Just click on my avatar, and scroll. You'll find it.
I had / have an ND alternator on my RV-6.
It was basically an automotive internally regulated one but with an aircraft company label on it.
After attending an aircraft wiring course I contacted the supplier (may have been PP - a few years ago now) about OV protection. I was told it was built in! I was a little dubious but left it at that.
A few months later I was in the cruise in close-ish formation. Did a panel scan: eeeek! Volts off the scale. Switched off alternator - no change. The ND start wire is just that: it turns the alt on but after that it becomes self energising.
Turned off the master. That 'fixed' it by blowing what was left of the internal regulator to heck.
Took the alternator apart, removed the regulator unit, modified the controlling brush to wire it to the 'start' terminal to turn it into a 'B&C'-a-like alternator, and fitted an external LR3C.
Been fine ever since, about 300 hours.
It was basically an automotive internally regulated one but with an aircraft company label on it.
After attending an aircraft wiring course I contacted the supplier (may have been PP - a few years ago now) about OV protection. I was told it was built in! I was a little dubious but left it at that.
A few months later I was in the cruise in close-ish formation. Did a panel scan: eeeek! Volts off the scale. Switched off alternator - no change. The ND start wire is just that: it turns the alt on but after that it becomes self energising.
Turned off the master. That 'fixed' it by blowing what was left of the internal regulator to heck.
Took the alternator apart, removed the regulator unit, modified the controlling brush to wire it to the 'start' terminal to turn it into a 'B&C'-a-like alternator, and fitted an external LR3C.
Been fine ever since, about 300 hours.
keijidosha
Member
Auto-nator
45 amp ?Denso? 14684 alternator w/ internal regulator and AeroElectric over-voltage crowbar mod purchased Sept 2010. Installed on O-320 with blast tube, VFR panel, incandescent lighting. Flying since 2014, currently has 120 hours. Too young to vote.
45 amp ?Denso? 14684 alternator w/ internal regulator and AeroElectric over-voltage crowbar mod purchased Sept 2010. Installed on O-320 with blast tube, VFR panel, incandescent lighting. Flying since 2014, currently has 120 hours. Too young to vote.
F1Boss
Well Known Member
Still working! *Well, not so much, really...*
PP gear drive primary unit - one of the prototypes. 225hrs so far - just had to replace the shear coupling (August 2016). ACS has these couplings for $15 ea - Hartzell (new owners of PP) wanted a smooth $100 for one.
This on a 550 Continental - very smooth running engine. I doubt this was a vibration related issue.
I have seen 35A charge out of this unit; normal load is 7-8A or so. No blast tube installed.
I'll NOT have one of these on my next bird. Ordered up 2ea B&C gear drive 40A units - one to replace this one, and one for the next build.
BTW it seem many RV pilots come to Taylor Texas to let their alternators die in peace. I keep an O/H'd ND on the shelf, and since the last go-round, I also keep spare brushes and rectifier assys on the shelf too. I'm getting too good at changing the rectifier assy out! Our local alternator shop wonders how is it that I work on so many alternators?
Carry on!
Mark
PP gear drive primary unit - one of the prototypes. 225hrs so far - just had to replace the shear coupling (August 2016). ACS has these couplings for $15 ea - Hartzell (new owners of PP) wanted a smooth $100 for one.
This on a 550 Continental - very smooth running engine. I doubt this was a vibration related issue.
I have seen 35A charge out of this unit; normal load is 7-8A or so. No blast tube installed.
I'll NOT have one of these on my next bird. Ordered up 2ea B&C gear drive 40A units - one to replace this one, and one for the next build.
BTW it seem many RV pilots come to Taylor Texas to let their alternators die in peace. I keep an O/H'd ND on the shelf, and since the last go-round, I also keep spare brushes and rectifier assys on the shelf too. I'm getting too good at changing the rectifier assy out! Our local alternator shop wonders how is it that I work on so many alternators?
Carry on!
Mark
Last edited:
Toobuilder
Well Known Member
70 amp ND from NAPA auto parts. 300+ hours on the Rocket with no issues
Bill Dicus
Well Known Member
Keijidosha! Could you show your wiring scheme for the OVP? Thanks in advance..
keijidosha
Member
Not my drawing, but similar to what I have http://www.aeroelectric.com/Catalog/AEC/9003/CbOV-14_Installation_A.pdf
Bill Dicus
Well Known Member
Keijidosha: Thanks - got and will wire it up soon. Sorry for slow response!
hgerhardt
Well Known Member
It seems to me that most of us on this board look at alternators as a monolithic entity, when really they are an assembly of fairly simple parts.
Plane Power and B&C both start out as Denso alternators. PP makes a mod to the internal reg to have absolute control over field current + adding an overvoltage module, while B&C uses a version similar to what older Chryslers had with an external regulator.
It sure would make this poll more useful if all the people who responded that they had a failure would just disassemble their units and diagnose what actually failed. Maybe we can find a pattern of similarly failed parts and come up with fixes to improve reliability. If you don't know about the inner workings of an alternator, go find someone who does know.
So far, this poll is nothing but a Ford vs. Chevy battle. Let's improve it!
Heinrich
Generic Denso alternator:
Plane Power:
B&C:
Notice how they all pretty much look the same?
Plane Power and B&C both start out as Denso alternators. PP makes a mod to the internal reg to have absolute control over field current + adding an overvoltage module, while B&C uses a version similar to what older Chryslers had with an external regulator.
It sure would make this poll more useful if all the people who responded that they had a failure would just disassemble their units and diagnose what actually failed. Maybe we can find a pattern of similarly failed parts and come up with fixes to improve reliability. If you don't know about the inner workings of an alternator, go find someone who does know.
So far, this poll is nothing but a Ford vs. Chevy battle. Let's improve it!
Heinrich
Generic Denso alternator:
Plane Power:
B&C:
Notice how they all pretty much look the same?
Captain_John
Well Known Member
It seems to me that most of us on this board look at alternators as a monolithic entity, when really they are an assembly of fairly simple parts.
Plane Power and B&C both start out as Denso alternators. PP makes a mod to the internal reg to have absolute control over field current + adding an overvoltage module, while B&C uses a version similar to what older Chryslers had with an external regulator.
It sure would make this poll more useful if all the people who responded that they had a failure would just disassemble their units and diagnose what actually failed. Maybe we can find a pattern of similarly failed parts and come up with fixes to improve reliability. If you don't know about the inner workings of an alternator, go find someone who does know.
So far, this poll is nothing but a Ford vs. Chevy battle. Let's improve it!
Heinrich
Generic Denso alternator:
Plane Power:
B&C:
Notice how they all pretty much look the same?
This proves that looks can be deceiving.
In all instances where those that I know have returned their PP alternators for repair (there are more than a few) they simply get another unit as a replacement and no description of what had actually failed.
In one instance the pilot knew it was bearing failure, as the rotor shaft was clearly wobbling.
This thread is just a collection of empirical data graphing the failure of each brand of alternator. Sure, you could do the same with Ford and Chevy, but this is much more specific than that.
Great topic! Great data!
What would make it even better is if you could go out to 500, 1,000 and more hours!
CJ
hgerhardt
Well Known Member
Exactly! And that's the problem with this poll. If people would just (carefully) take apart their alternators and diagnose what actually went wrong before returning them, that would be a nice benefit for us.
Captain_John
Well Known Member
Well, then according to this poll we would have exactly one B and C alternator to examine but many, many, many, more Plane Power units to look at.
CJ
CJMy Plane Power voltage regulator failed going to high voltage and then shutting down. Recycling the alternator made no difference the unit would not come back on line. I was stranded in Montrose Colorado(a great place to be stranded), on my way back to Denver from California with 12 months since my maiden flight and only 77 hours on the Hobbs. The failure occured immediately after startup, so I decided to fix the problem and not push a two hour flight over the continental divide on just battery power. Given the challenge of rewiring the plane to handle a separate voltage regulator, with limited tools, I decided to have Vans drop ship me a new one overnight. Vans did a great job in getting the part out the door. I replaced the AL12-EI60/V which now has a new Hartzell model number 99-1012. With the new alternator installed everything was good for a beautiful flight home.
Now that I am back home I called Plane Power( Hartzell.aero) to find out about their warranty. They said that the two years starts when the unit is sold out the door. Since I got the alternator as part of my firewall forward kit I do not make the two year cut off. Needless to say I expressed some frustration over this response.
They also said they do not fix the alternators but there is a repair kit available from Aircraft Spruce- part number 07-17968 ($79). He also directed me to the web site for the instructions.
http://www.plane-power.com/ICA.php
This looks like an easy field repair and might be an part to consider carrying if your are running a Plane-Power Alternator. Does anyone have experience with this repair?
Jeff Jones
Broomfield Colorado
RV-7A IO-360 A1B6
Now that I am back home I called Plane Power( Hartzell.aero) to find out about their warranty. They said that the two years starts when the unit is sold out the door. Since I got the alternator as part of my firewall forward kit I do not make the two year cut off. Needless to say I expressed some frustration over this response.
They also said they do not fix the alternators but there is a repair kit available from Aircraft Spruce- part number 07-17968 ($79). He also directed me to the web site for the instructions.
http://www.plane-power.com/ICA.php
This looks like an easy field repair and might be an part to consider carrying if your are running a Plane-Power Alternator. Does anyone have experience with this repair?
Jeff Jones
Broomfield Colorado
RV-7A IO-360 A1B6
scsmith
Well Known Member
bad/weak plug contacts
Some fraction of the plane-power alternator 'failures' are high voltage symptoms because the contacts inside the plug for the field circuit don't stay tight. This happened to me and many others I bet. Thanks to Dan H and a few others that pointed this out. Pinching the contacts and potting the back of the plug with RTV seems to have solved it for me.
Some fraction of the plane-power alternator 'failures' are high voltage symptoms because the contacts inside the plug for the field circuit don't stay tight. This happened to me and many others I bet. Thanks to Dan H and a few others that pointed this out. Pinching the contacts and potting the back of the plug with RTV seems to have solved it for me.
BillL
Well Known Member
If that is what failed, no problem. It might be prudent to take it to an alternator shop and have it tested first.
Last edited:
Well, then according to this poll we would have exactly one B and C alternator to examine but many, many, many, more Plane Power units to look at.
Careful, a PP owner will surely declare your conclusion statistically invalid
BillL
Well Known Member
and . . . .
Maybe the rotors are better balanced. Maybe the wire is not as stiff. Maybe they have better (any) strain relief (wire to connector).
Maybe the rotors are better balanced. Maybe the wire is not as stiff. Maybe they have better (any) strain relief (wire to connector).
alpinelakespilot2000
Well Known Member
It's not just the connectors. I checked mine (because I had the benefit of having read DanH's experience), but also when Hartzell got called on my Plane Power they pretty much admitted that I wasn't the only one reporting problems, that one of the major problems reported were broken stators (or something like that), but that also there were repair kits available from ACS (mentioned above) that would address that or a different issue. They weren't sure. In short, there seem to be multiple issues at work and, what was worse, they had no interest in and were completely unwilling to look at, let alone repair mine. That said a lot to me.
fl-mike
Well Known Member
Steve,
You are right on the money, literally, except not a spring but a grommet seal/support:
Mating Connector: DM2085 $6.99
Pins: DM3284 $0.69
Seals: DM1598 $0.50 <<<<<
(driftmotion.com)
My latest PP failure was due to a broken pin in the mating connector due to vibration fatigue because PP did not use the seal/support on the pre-wired mating cable. RTV'em guys.
My original Van's 60 amp unit lasted approx. 500 hrs. I have a blast tube. I bought a replacement at Advance Auto about 125 hrs ago. Lifetime warranty. Out the door for $100.
The Van's internal voltage regulator was failing. It was burying the needle on Van's voltmeter. After removing the unit, I also found the bearings to be bad.
The Van's internal voltage regulator was failing. It was burying the needle on Van's voltmeter. After removing the unit, I also found the bearings to be bad.
scsmith
Well Known Member
Could you list a make/model car that has a drop-in replacement for the Plane Power (i.e. internally regulated) so if I ever need to resort to an automotive solution I can get one easily?
scsmith
Well Known Member
I just wonder, if all the cores are made by Denso, then why the difference in stator life, bearing life, wire stiffness, internal strain relief? Wouldn't those all be the same from the same manufacturer?
And..
If Hartzell is so disinterested in servicing, diagnosing, improving, the Plane Power unit, why did they buy out PP?
And..
If Hartzell is so disinterested in servicing, diagnosing, improving, the Plane Power unit, why did they buy out PP?
alpinelakespilot2000
Well Known Member
This is promising news. And very definitely a change in policy from what I, and apparently a number of others, have previously (and fairly recently) been told by Hartzell.
BillL
Well Known Member
Steve, one from a 1997 Toyota Paseo is about as close I have found. There is a 60A and 70A. One thing, though, the PP unit does not have the rear housing as part of the mount, but the Paseo does. They are not cheap, though, a good rebuilt Denso or Bosch is $230 of so. Maybe just fine as Denso should built it to factory specs - new (original spec) bearings etc. The clocking of the mount-to-tensioner is the same. Still less than $400. And maybe more reliable.
You might look up at a local parts supplier and go have a personal examination. I would check, clocking, length of mount and bolt hole size, B+ post orientation, and connector plug. Oh - and I don't remember if it has a v-belt pulley. It IS the same stator/rotor so if your installation was tight, the housing should fit without mods. I would do it but am focused on first flight. Let us know what you find.
Added: There are a ton of will-fit parts. I would not surprised of none of the PP (60A) parts are actually made by Denso.
Last edited:
scsmith
Well Known Member
Bill, that statement caught me off guard. My impression was that they started with a Denso alternator, turned the cooling fan around, put a different regulator and a different pulley on it and shipped it. My impression is no doubt wrong.
Looking at the photos posted, the castings are not the same on any of them. So it does beg the question.
DwightFrye
Active Member
Slow Death?
So I've been a bit unhappy with how my PlanePower alternator has been behaving. For the PC-680 battery to be really happy it needs a charging voltage of about 14.5v, as I understand it. My alternator -had- been putting out 14.0v, as measured by my EFIS. I now notice that in cruise flight I'm only getting 13.9v, and since it is internally regulated there is nothing to be done about it.
At this point my feeling is that my battery is being recharged slowly, and may not ever be making it to a full charge. This seems .. to put it bluntly .. not good.
I'm looking for an opinion. Is this the early stages of an inevitable slide toward alternator failure? If I don't switch it out now am I just going to be replacing batteries until the alternator totally croaks and I have to replace it anyway? Or am I being alarmist, and should just shut up and go fly?
I actually think I voted too early in the poll. I knew mine was iffy, but it had not "hard failed" so I indicated I had not had a failure. But I might be wrong, and it just might be a slow failure rather than a catastrophic one.
Opinions? Is it time to pull it out before I DO end up with a hard failure? If I do pull it out, I'm inclined to go the B&C route myself.
So I've been a bit unhappy with how my PlanePower alternator has been behaving. For the PC-680 battery to be really happy it needs a charging voltage of about 14.5v, as I understand it. My alternator -had- been putting out 14.0v, as measured by my EFIS. I now notice that in cruise flight I'm only getting 13.9v, and since it is internally regulated there is nothing to be done about it.
At this point my feeling is that my battery is being recharged slowly, and may not ever be making it to a full charge. This seems .. to put it bluntly .. not good.
I'm looking for an opinion. Is this the early stages of an inevitable slide toward alternator failure? If I don't switch it out now am I just going to be replacing batteries until the alternator totally croaks and I have to replace it anyway? Or am I being alarmist, and should just shut up and go fly?
I actually think I voted too early in the poll. I knew mine was iffy, but it had not "hard failed" so I indicated I had not had a failure. But I might be wrong, and it just might be a slow failure rather than a catastrophic one.
Opinions? Is it time to pull it out before I DO end up with a hard failure? If I do pull it out, I'm inclined to go the B&C route myself.
F1Boss
Well Known Member
Easy fix?
You could go to a genuine alternator shop and ask 'em to install a regulator set at 14.5v. Or, you could buy said regulator and put it in yourself - takes about 15 min to do this. The ND regulators fit perfectly, so either option is viable in your case.
As I mentioned in another post, ,it seemed that fellas bring their plane here to let their alternators die in peace. I take 'em to a local shop for a new regulator, or I do it myself if I have one on the shelf. Piece o cake to do this fix.
That being said, I have removed the PP gear drive alt from my plane after repeated shear coupling failures @225TTSNEW, and installed the B&C version with the remote and ADJUSTABLE regulator. This action also keeps me from whining to HET, who don't seem to care.
Carry on!
Mark
You could go to a genuine alternator shop and ask 'em to install a regulator set at 14.5v. Or, you could buy said regulator and put it in yourself - takes about 15 min to do this. The ND regulators fit perfectly, so either option is viable in your case.
As I mentioned in another post, ,it seemed that fellas bring their plane here to let their alternators die in peace. I take 'em to a local shop for a new regulator, or I do it myself if I have one on the shelf. Piece o cake to do this fix.
That being said, I have removed the PP gear drive alt from my plane after repeated shear coupling failures @225TTSNEW, and installed the B&C version with the remote and ADJUSTABLE regulator. This action also keeps me from whining to HET, who don't seem to care.
Carry on!
Mark
alpinelakespilot2000
Well Known Member
You may be just fine. If you search the threads a bit you'll notice that many have reported that their EFIS's read about .3 or .4 volts lower than what the battery is seeing. This is certainly true for me and my Dynon D180 which reads about 0.3V lower than my main bus. Something about diodes in the EFIS or something like that. You should check yours if you haven't already.
The other thing, while there may be an "ideal" for Odyssey batteries in theory, there also seems to be a pretty good history of Odyssey's going long with a variety of voltages. Have you been having troubles with your battery? If not, I wouldn't worry too much about what your voltmeter reads as long as its reasonable.
Last edited:
DwightFrye
Active Member
Actually, I have had some trouble. My first PC-680 went for years, but the second one died within a year. My third left me unable to crank at Osh, but revived after about an hour on a charger. That was after two very short legs as I worked my way through the WX, each (obviously) with an engine crank event. My sense is that a few cranks with only a 15 minute flight to recharge left my battery weak. So my confidence in the charging behavior has become diminished.
dave4754
Well Known Member
Prestolite
I am building and intending to use a rather heavy Prestolite alt, it came with the engine but from what i have heard here Plane Power alt. fail.
So i am about to use the Prestolite with a Plane power regulator, any comments or ideas on that ? hmmm is this taking advantage of the OP?
If so please disregard.
I am building and intending to use a rather heavy Prestolite alt, it came with the engine but from what i have heard here Plane Power alt. fail.
So i am about to use the Prestolite with a Plane power regulator, any comments or ideas on that ? hmmm is this taking advantage of the OP?
If so please disregard.
Vans 60 amp started playing up (occasionally dropping off line) after 300 hours replaced the regulator ( cheap fix) and it's been fine the last 200 hours.
It would just occasionally stop charging at low rpm. So never really let me down.
As the aircraft is setup for it, I'm happy if occasionally I have to replace the regulator.
For my -10 I've gone externally regulated. With a PP 70 amp which came with my engine and a B&C standby vacuum pad alternator.
It would just occasionally stop charging at low rpm. So never really let me down.
As the aircraft is setup for it, I'm happy if occasionally I have to replace the regulator.
For my -10 I've gone externally regulated. With a PP 70 amp which came with my engine and a B&C standby vacuum pad alternator.
540 Hours ... no blast tube ... no issues
B&C 60 Amp with B&C Regulator.... 5 years .... 540 Hours .... no blast tube .... no problems.
RV7a O-360 CS
I really like the B&C stuff, looks good usually is good and there stuff is nice. Pricy but nice I'd do it again.
Bill
B&C 60 Amp with B&C Regulator.... 5 years .... 540 Hours .... no blast tube .... no problems.
RV7a O-360 CS
I really like the B&C stuff, looks good usually is good and there stuff is nice. Pricy but nice
I'd do it again. Bill
[email protected]
Member
Plane Power 60 amp alternator FAILED with less than 250 hours
I have a Plane Power 60 amp Model AL12-EI60/V (PP) it has failed at 85 hours. I purchased a new IO-360 engine from Vans fall of 2013 and started flying June of 2016. The PP came with the engine and has approximately 9 calendar months of flying time. I called PP and I was told the 2 year warranty is from time of purchase and they would not replace it. This is the only company I dealt with that has enforced this policy.
If I was in the building phase, I would not purchase anything from this company. The alternator was out of warranty before my first engine start.
I have a Plane Power 60 amp Model AL12-EI60/V (PP) it has failed at 85 hours. I purchased a new IO-360 engine from Vans fall of 2013 and started flying June of 2016. The PP came with the engine and has approximately 9 calendar months of flying time. I called PP and I was told the 2 year warranty is from time of purchase and they would not replace it. This is the only company I dealt with that has enforced this policy.
If I was in the building phase, I would not purchase anything from this company. The alternator was out of warranty before my first engine start.
kevinsrv7.com
Well Known Member
I have a Plane Power 60 amp Model AL12-EI60/V (PP) it has failed at 85 hours. I purchased a new IO-360 engine from Vans fall of 2013 and started flying June of 2016. The PP came with the engine and has approximately 9 calendar months of flying time. I called PP and I was told the 2 year warranty is from time of purchase and they would not replace it. This is the only company I dealt with that has enforced this policy.
If I was in the building phase, I would not purchase anything from this company. The alternator was out of warranty before my first engine start.
Thanks for sharing your experience. Could you give details of the symptoms of your alternator failure so others have a heads up!
