Electrical issue.....please help

[Piloto]

Bnicolette

Looks like your problem may be related to an open diode in the alternator. Alternators are three phase AC generators with a pack of six diodes to convert the AC voltage into DC. When one of the diodes is open the alternator voltage drops significantly at idle under load but recovers back to normal at high RPM. You can over rule the regulator by connecting the field directly to the battery bus or alternator output and running the engine at idle. If the voltage falls at idle under normal load then you have an open diode. Diodes are prone to fail by lightning strike either in flight or tied down or poor alternator cooling under heavy load.

José

[duke]

does not need to be runnin--just master, ignition and alt switches on and field wire connected to alt

[N201MKTurbo]

Every time I have had a diode failure or a stator winding failure, you will get a noticeable high pitched whine in your radios that varies with RPM. In most cases if an alternator drops a single phase it will still work good enough. After it drops the second phase, it'll barely run the radios and the whine will be very loud. I have repaired quite a few alternators for cars and aircraft, all diode failures have been mechanical, not an actual failure of the diode. The diodes work loose from their mounts or their leads fracture from vibration or thermal cycling.

Hot wireing the field as Jose suggests is a good way to verify that the alternator is working, just don't let it go very long or it will ruin your battery, and make sure you disconnect the regulator when you do this or you could ruin the regulator.

[N201MKTurbo]

I want Duke's alternator, I could solve the energy crisis

[Piloto]

Every time I have had a diode failure or a stator winding failure, you will get a noticeable high pitched whine in your radios that varies with RPM.

The above is more common on old audio systems sharing a common ground with power ground. On most new airplane wiring the audio ground is separate from the power ground to avoid power ground ripples from getting into the audio system. The old jets were recognized on the radio by the 400Hz tone in the background due to power ground sharing. For long run audio wiring like on four place intercom it is recommended to carry a separate ground wire rather than just grounding to the airframe, This will keep the audio system clear of ground power noise.

José

[Alan Fox]

Every time I have had a diode failure or a stator winding failure, you will get a noticeable high pitched whine in your radios that varies with RPM. In most cases if an alternator drops a single phase it will still work good enough. After it drops the second phase, it'll barely run the radios and the whine will be very loud. I have repaired quite a few alternators for cars and aircraft, all diode failures have been mechanical, not an actual failure of the diode. The diodes work loose from their mounts or their leads fracture from vibration or thermal cycling.

Hot wireing the field as Jose suggests is a good way to verify that the alternator is working, just don't let it go very long or it will ruin your battery, and make sure you disconnect the regulator when you do this or you could ruin the regulator.

Jumping the alternator field wire is not a smart way to diag the alternator , you can fry any or all of the electronics on the bus.......

[Piloto]

Jumping the alternator field wire is not a smart way to diag the alternator , you can fry any or all of the electronics on the bus.......

There is a possibility of a higher voltage at high rpm. However having the battery on line and running the engine at idle or less than 1000 rpm will insure a safe voltage. You can also turn off the avionics master off and just use the landing light as a load. Keep an eye on the voltmeter to check alternator performance.

José

[RJBrown]

name='Bnicolette' timestamp='1354929318' post='83272']

The hours are ticking up as he troubleshoots this!!

Seeing statements like this boil my blood. Something HE did is causing the problem. You should not have to pay extra for him to find his mistake. No one in the car repair business would last very long charging extra to fix their own mistakes.

We as a group are a bunch of suckers to fall for this garbage.

On Dec 1st I got my plane back from an engine O/H. They hired a pilot to bring it over and I flew him back to Montrose. I walked up as he got out of my plane on APA. He told me the fuel flow gauge was erratic. So before we took off I called Wester Skyways to alert them to the need to recheck the work. The person on the other end got nasty and ask if I were accusing them of something. I sad no I just wanted to alert them that it needed looked at when I arrived. He then got even nastier and said no one does that on Saturday and that I was going to have to live with it. Well I got nasty back and told them to sue me for the balance due and that I would have someone else check their work. Shortly thereafter the guy I had been working with called me and ask that I give him a chance to address the issue. Sure enough a wire connection was loose and got fixed. NO EXTRA CHARGE!!

If I ran my auto repair shop like all these airplane repair shops are run I would not be able to own and fly my own airplane.

Turns out it was the owner of the company with the bad people skills while the IA/AP I dealt with was a great guy putting out the fire his boss caused.

Don't put up with this kind of abuse and maybe they will improve their diagnostic skills and the problem will end. To pay people more money to cover incorrectly done work is crazy. It works against getting proper work in the first place.

Airplanes are NOT complicated machines. There is nothing special about them. Cars are way more complicated. Don't be fooled by the mystique of it being an airplane. This is 50's technology it ain't rocket science. Don't put up with "parts changers" either. The lets just keep changing parts until the magic happens is just stupid.

[bnicolette]

RJ, That's awful that the owner of the company was less concerned about helping you out than one of his employees!! I'm glad it worked out in a positive way for you though.

I don't think my shop/mechanic will charge me for all this troubleshooting but that has yet to be seen. I haven't addressed it with him yet either as I don't want to rock the boat until this is all figured out. He is a straight laced individual with values, so I am hoping for the best.

I wish I could be there today while he's working on it but instead I'm sitting in Teterboro bored out of my mind. (On my birthday even!) Thank goodness for Mooneyspace.

[Marauder]

RJ, That's awful that the owner of the company was less concerned about helping you out than one of his employees!! I'm glad it worked out in a positive way for you though.

I don't think my shop/mechanic will charge me for all this troubleshooting but that has yet to be seen. I haven't addressed it with him yet either as I don't want to rock the boat until this is all figured out. He is a straight laced individual with values, so I am hoping for the best.

I wish I could be there today while he's working on it but instead I'm sitting in Teterboro bored out of my mind. (On my birthday even!) Thank goodness for Mooneyspace.

Ah Teterboro! Brings back memories. Hauling checks to Hartford as a Freight Dog...

[N601RX]

Trouble shooting a non working alternator should take less than 1hr, and doesn't involve replacing the battery and voltage regulator without knowing they are bad. With a meter and the KNOWLEDGE to use it, it only takes a few minutes. Randomly changing parts is not the answer. I've saw some very good mechanical guys, but electrical stuff was just not their thing.

[bnicolette]

Well the verdict is in apparently. He claims it is the alternator.

It is going back to Plane Power and possibly will be covered under warranty. However, I can't imagine what could have happened to it. The system was working fine when I taxied it over to his hangar before we pulled the engine and now suddenly there is a problem with it when the engine goes back on?

Hopefully Plane Power will be able to give me some clues as to the possibilities.

Thank you everybody for your input. I certainly hope when that thing goes back in that it was indeed the problem and this situation is done!

[Alan Fox]

It is possible that the main lead out of the alternator was tightened too tight and possibly broke the rectifier assy , lets hope thats not the case......

[Piloto]

RJ Brown

I don't know where you have your car repair but car repairs are not cheap either. My experience has been $400 total for a two hours job, $200/hour?. And none of those parts in a car are FAA-PMA to be so expensive. Talking about services my sister was charged $180 for a toilet repair. You can get the whole overhaul kit at Home Depot for $11.00. So what is the remaining $169 for. I am going to switch job and become a morrocollo. I heard they make more money than a pilot and they are always in need.

José

[Alan Fox]

RJ Brown

I don't know where you have your car repair but car repairs are not cheap either. My experience has been $400 total for a two hours job, $200/hour?. And none of those parts in a car are FAA-PMA to be so expensive. Talking about services my sister was charged $180 for a toilet repair. You can get the whole overhaul kit at Home Depot for $11.00. So what is the remaining $169 for. I am going to switch job and become a morrocollo. I heard they make more money than a pilot and they are always in need.

José

The remaining 169 is for someone to come out to your house , travel time ,a yellow pages ad, a trip to home depot , insurance , cleaning supplies , gas , and the actual repair..... Just because we can do it ourselves , dont begrudge someone else the right to earn a living...... Think about it the whole thing is a three hour job , if he spends an hour at the house thats 56 dollars an hour , minus expenses.... When you think about it , its actually not a bad price...

[Piloto]

The remaining 169 is for someone to come out to your house , travel time ,a yellow pages ad, a trip to home depot , insurance , cleaning supplies , gas , and the actual repair..... Just because we can do it ourselves , dont begrudge someone else the right to earn a living...... Think about it the whole thing is a three hour job , if he spends an hour at the house thats 56 dollars an hour , minus expenses.... When you think about it , its actually not a bad price...

Good points. Next time I'll bring the toilet to the plumber. BTW it was no more than half an hour to fix the toilet and he had all the parts on his van.

José

[Alan Fox]

Good points. Next time I'll bring the toilet to the plumber. BTW it was no more than half an hour to fix the toilet and he had all the parts on his van.

José

I have an auto repair shop Hose' and people balk at 84 an hour......My break even is about 18000 a month in sales....That means of the first 900 a day I bill in parts and labor I make 0 dollars.......anything over that I make minus parts and supplys......3500 rent , insurance , phones , advertising , labor , tools , data service, credit card processing , paper , etc etc.....I fix it right the first time , I charge a fair rate , I dont put on customer supplied parts.... I sell parts at a profit to earn a living.... And Ive been in buisness 20 years and always have work.... Go Figure....

[Piloto]

I have an auto repair shop Hose' and people balk at 84 an hour......My break even is about 18000 a month in sales....That means of the first 900 a day I bill in parts and labor I make 0 dollars.......anything over that I make minus parts and supplys......3500 rent , insurance , phones , advertising , labor , tools , data service, credit card processing , paper , etc etc.....I fix it right the first time , I charge a fair rate , I dont put on customer supplied parts.... I sell parts at a profit to earn a living.... And Ive been in buisness 20 years and always have work.... Go Figure....

$84/hour that's not bad. Next time the toilet breaks I'll give you a call.

José

[RJBrown]

RJ Brown

I don't know where you have your car repair but car repairs are not cheap either. My experience has been $400 total for a two hours job, $200/hour?. And none of those parts in a car are FAA-PMA to be so expensive. Talking about services my sister was charged $180 for a toilet repair. You can get the whole overhaul kit at Home Depot for $11.00. So what is the remaining $169 for. I am going to switch job and become a morrocollo. I heard they make more money than a pilot and they are always in need.

José

I own a car repair shop, have for over 31 years. If pilots were treated the way I treat drivers this would not be an issue. I charge $95 an hour. At $95 I am slightly higher than my local MSC. My complaint is not about labor rates. My complaint is about the propensity of airplane mechanics to charge for repairing their own mistakes and for bumbling around not knowing what to fix and charging for "learning". Learning how to fix something is not the responsibility of the car/plane owner. A mechanic should know his job, he should not charge a higher time because he had to learn. We use a flat rate manual to determine labor costs. The job pays a certain amount. If an inexperienced man takes longer than it should to fix something it should not cost more. Conversely if an experienced man can fix it quickly he should not be paid less.

[Alan Fox]

$84/hour that's not bad. Next time the toilet breaks I'll give you a call.

José

You couldnt pay me enough to work on equipment that people poop in....

[N601RX]

Any update?

[bnicolette]

Any update?

Yes......Sorry I forgot to post.

The alternator was sent back to Plane Power. It was found to be defective and they (Plane Power) covered it under warranty and expedited it back to us. Apparently there was a stator wire (?) loose and was contacting the side of the unit or something it shouldn't have been which was causing my issue.

I think part of the troubleshooting problem here is that the alternator was not completely dead and was putting out but just not what it was supposed to. The other problem is that this alternator was installed in June of this year and only had 25 or so hours on it. So it was hard to fathom that something had happened to it. Oddly enough it worked fine before the engine removal and then didn't when it was reinstalled.

I am happy to report that when we installed the alternator that I had a steady 14.1 volts on the JPI from startup to shutdown and it was steady as a rock from idle thru full power.

Through this process I have a new Zeftronics regulator (R15300) and a new Concorde battery (R35AXC). I have been wanting to upgrade to the Concorde battery anyhow but my old voltage regulator would not play well with the sealed battery so I was unable to do so. So, all is not lost.

Anybody need a voltage regulator? part #: VR415F

Thanks again to everybody for all their input!!!!