Need help trouble shooting Alternator

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  • #84362

    Well flying back Sunday I was at FL210 and my right alternator light came on failed. I checked to see if it had any pull on it and it didn’t. I went a head and shut it off, thinking I would try it again and light kinda flickered and that was it still not working so I landed in Oklahoma and before my shut down I thought I would check again and sure enough light went out I shut left alternator off to make sure it was getting a good load and it was no problem. Any suggestions? I did just get it out of annual before I left

    Thanks In ADVANCE

    #99726

    After resetting the Alt switch, did it come back on even momentarily or was the light on immediately? If it did come back on when you were on the ground then I assume the field fuse or circuit breaker were not tripped or blown.

    I had an alternator ghost for a while and would observe different behavior on the ground vs in the air. Turned out to be my voltage regulators. One of my alternators is very weak so the VR’s kept kicking each other off because of the imbalance. I’m in the process of replacing both of them as well as the alternators will all PlanePower components.

    #99727

    I would check the wires to the alternator and make sure they are correct. Does the alternator “whine” differently then the other (noise in the headsets). If you run each alternator on it’s own, what voltage is it regulating to?

    Eric

    #99728
    quote RGould1:

    … sure enough light went out I shut left alternator off to make sure it was getting a good load and it was no problem. Any suggestions?

    In addition to the other comments, I had a similar experience last year. When they disassembled the alternator at the overhaul shop they found the problem to be in stator windings – when they were warm / hot they would short and when they were cool the alternator would operate normally. That is one of probably 10 failure modes associated with the alternator system so it is difficult to tell what your source is.

    If you are not going to upgrade to one of the new generation alternators I have a freshly overhauled ALV9510 and regulators if you need it / them.

    Geoff

    #99734

    ok.Thank for all the responses when back on thrground it worked great I will check for whine. shoot me a email on rebilt alternator gouldracing05@yahoo.com. Thanks to all

    #99829

    thank for all the help it was a bad connection on the crimped end that bolts on alternator thanks so much for thisgreat group its worth the price to be a part of this great group with so much knowledge

    #99831

    I have buzzing from both alts has anyone had luck with the inline filters?

    Rocky Hill

    #99872

    While on a flight from OklahomaCity to Bremerton Washington I stopped into Broomfield Colorado for fuel. We had filed
    an Instrument flight plan because of weather situations, in moderate Ice, nothing bad.. While parked at Legacy air a
    terrible rain and lightning storm came over the field.More thunder and lightning than than I have experienced in a long
    time(being from Oklahoma that,s saying something) thunder roared ,and cloud to ground lightning every where.
    We had unloaded our bags deciding to spend the night in Broomfield. While the passengers stood inside of Legacy,s
    hangar I had one more bag to get out of my 421 left wing locker ,which I decided to brave the elements to get.
    I opened the left wing locker and grabbed the bag and went to place it on the ground when a hugh thunder blast and
    a lighting bolt caused me to duck lower to the ground,it was then I saw a thread of electrical charge arc from my rear side of the left wing to to an area by the passenger door. The skin of the air craft hummed and a harmonic type vibration
    went along the surface of the aircraft. It was very hard to believe what I was seeing. I ran for the protection of the
    hangar and asked my passengers who had heard the event if they saw lightning hit my plane. They said they say the flash and heard the noise but could not verify the strike. We went to Hotel ,spent the night,got back to airport next morning early. All passengers loaded ,pre flight completed IFR plan loaded into Gps we taxied to take off,forgetting all about the strike.
    Flight service had our flight plan filed under the wrong tail number so we waited a few minutes for the correction while waiting I checked my electrical system. No lights were noted indicating any problems . We took off had an uneventful flight
    to TwinFalls Idaho. Fueled up and began our final leg to Bremerton > About 50 miles out of twinfalls center requested we cycle our transponder ,as we were doing this we had a total power failure. We lost everthing electrical . We dialed in lost com on transponder and turned back to Twinfalls using our I pod for navigation. Thankk goodness we were not in IMC conditions,that would have been a very difficult situation.I did have a back up attitude indicator with a battery back, this unit spun about 30 times and died ,so much for that. We got back to Twinfall ,had to blow the gear down to land.Made the required phone calls to the tower and center then the wonderful folks at Reeder aviation helped us find a hotel a mechanic,and let us use a car .I cannot give enough praise to these folks .(Thanks again Reeders.) The mechanic
    thought it was a battery problem so we had a battery delivered the next day,placed it in the aircraft and fired it up no charging was taking place oh oh a bigger problem than we thought, with no immediate repair to be had. W rented are car and began our drive back to Oklahoma. We had been driving about a hour when Glen my passenger,and I remembered the lightning strike. The reason that I did not consider the strike to be a problem was because as close as I was I did not receive a shock from the strike. The hair an my arms and head stood up and I heard a hissing sound plus the indications I mentioned previously.I called the mechanic and told him of the strike, he began his investigation and sure enough the engines were magnetized all electrical responsible for the charging system were fried. Why the aircraft was able to have radio and navigation for two hour of flight confuses me .We did receive a voltage light when we left Broomfield as well as a right alt, light but they disappeared almost as soon as they were indicated . Left me thinking I had no problem. I did note that the charges being put out were minimal,,
    to less than minimal but i thought this was because I was placing less demand on the system
    I have been told that the engines must now be tore down and inspected ,and i do not have any thoughts on what other damage was done. If anyone has any advice for me I,m ready to hear from you Thanks gtrhornton

    #99873

    While on a flight from OklahomaCity to Bremerton Washington I stopped into Broomfield Colorado for fuel. We had filed
    an Instrument flight plan because of weather situations, in moderate Ice, nothing bad.. While parked at Legacy air a
    terrible rain and lightning storm came over the field.More thunder and lightning than than I have experienced in a long
    time(being from Oklahoma that,s saying something) thunder roared ,and cloud to ground lightning every where.
    We had unloaded our bags deciding to spend the night in Broomfield. While the passengers stood inside of Legacy,s
    hangar I had one more bag to get out of my 421 left wing locker ,which I decided to brave the elements to get.
    I opened the left wing locker and grabbed the bag and went to place it on the ground when a hugh thunder blast and
    a lighting bolt caused me to duck lower to the ground,it was then I saw a thread of electrical charge arc from my rear side of the left wing to to an area by the passenger door. The skin of the air craft hummed and a harmonic type vibration
    went along the surface of the aircraft. It was very hard to believe what I was seeing. I ran for the protection of the
    hangar and asked my passengers who had heard the event if they saw lightning hit my plane. They said they say the flash and heard the noise but could not verify the strike. We went to Hotel ,spent the night,got back to airport next morning early. All passengers loaded ,pre flight completed IFR plan loaded into Gps we taxied to take off,forgetting all about the strike.
    Flight service had our flight plan filed under the wrong tail number so we waited a few minutes for the correction while waiting I checked my electrical system. No lights were noted indicating any problems . We took off had an uneventful flight
    to TwinFalls Idaho. Fueled up and began our final leg to Bremerton > About 50 miles out of twinfalls center requested we cycle our transponder ,as we were doing this we had a total power failure. We lost everthing electrical . We dialed in lost com on transponder and turned back to Twinfalls using our I pod for navigation. Thankk goodness we were not in IMC conditions,that would have been a very difficult situation.I did have a back up attitude indicator with a battery back, this unit spun about 30 times and died ,so much for that. We got back to Twinfall ,had to blow the gear down to land.Made the required phone calls to the tower and center then the wonderful folks at Reeder aviation helped us find a hotel a mechanic,and let us use a car .I cannot give enough praise to these folks .(Thanks again Reeders.) The mechanic
    thought it was a battery problem so we had a battery delivered the next day,placed it in the aircraft and fired it up no charging was taking place oh oh a bigger problem than we thought, with no immediate repair to be had. W rented are car and began our drive back to Oklahoma. We had been driving about a hour when Glen my passenger,and I remembered the lightning strike. The reason that I did not consider the strike to be a problem was because as close as I was I did not receive a shock from the strike. The hair an my arms and head stood up and I heard a hissing sound plus the indications I mentioned previously.I called the mechanic and told him of the strike, he began his investigation and sure enough the engines were magnetized all electrical responsible for the charging system were fried. Why the aircraft was able to have radio and navigation for two hour of flight confuses me .We did receive a voltage light when we left Broomfield as well as a right alt, light but they disappeared almost as soon as they were indicated . Left me thinking I had no problem. I did note that the charges being put out were minimal,,
    to less than minimal but i thought this was because I was placing less demand on the system
    I have been told that the engines must now be tore down and inspected ,and i do not have any thoughts on what other damage was done. If anyone has any advice for me I,m ready to hear from you Thanks gtrhornton

    #99904

    Wow! I am glad you are safe, a total electrical failure is no fun in a twin. It is possible the plane started up and flew on battery power alone. The alt failure circuitry was probably blown too.
    I don’t agree at all with the engine tear down. There was no confirmed strike on the prop or the engine. From the sound of it, you saw the strike – probably a pre-strike “finger” discharge strike the aft area. Probably temporarily raised the voltage on the plane high enough to blow out the diodes on the alternator. I would replaces them with the lightweight Hartzell 9610’s. You might also replace the voltage regulators.

    Engine tear down on a lightening strike is if it hits the prop. It can blow off a tip, damage the hub,damage the crank, etc. No evidence you had this. If the engine is magnetized I would see if it impacts your compass. If it does not, I would not worry about it. The mounts are almost all aluminium.

    Also check grounds to all control surfaces, make sure they move free and clear, and check static wicks(electrical test)

    You had a near call for a full strike on you – glad you are safe!

    If you are having trouble with the shop I will dig up the electrical strike guidelines from TCM. Cessna probably also has some. Your insurance company should be notified and this is probably a covered claim. I would test everything electrical and also expect some things to fail over the next 6 months.
    I would send at least one Nav/comm out for bench test and let them know possible lightening strike.

    Good luck!

    #99994

    Thankyou EPANNING,
    The insurance has agreed to be involved with the repairs. The engines,cylinders,and props displayed high values of magnetism using a meter.The decision was to remove engines and send to RAM for a rear down and inspections. My right engine is new(50 hours) the left engine has high time but all numbers at annual were good , I had hoped to go 2 more years before rebuild but guess now is a good time. We have replaced all electrical charging components the engines were started and all charging tests were good. The insurance did not know if that liability was to be shared by them for the props but I chose to send them off for inspections and repairs. Everything is moving along on repairs but do not think I will see the plane for a few months. I am concerned about my radio and nav equipment.This will be dealt with when all is back together.
    I wonder how many aircraft have been struck by lightning and the owners not know it.? Had I not been at the airplane I would not have known it was struck . I am in Oklahoma and the plane is in Twinfalls Idaho, when the mechanic gets a chance he is going to give everything a good once over. Thankyou for your input. I did not intend steal this post but the the subject was perfect.gthornton

    #99995

    Do you know what style meter they used, and what values they were looking at? Were both engines equal? was the gear magnetic? (I ask because most of the engine/prop is aluminum which is not magnetic. The crank is, do they degauss it?

    I guess the most important is you are safe. You probably experienced some significant electric fields. Any metal fillings? You might have felt shock there.

    I would also have the shop test your static wicks (need a special meter)

    Eric

    #100016

    We’re are you home airport here in oklahoma? we are ast sre. seminole oklahoma

    #100033

    Ron my home airport is Khsd (Sundance). Eric ,I did not feel any electrical gharge on my person, Idon,t know if the gear was charged or not. The readings were not all equal some were on the positive side of the device and some read negative.
    As this repair continues forward I will follow the advice I am receiving . This is all greek to me.
    For any of you who were in the service in a combat zone this experience I had with the lighting was like a mortar going off right next to your fox hole, the only thing I wanted to do was get as low as I could.I was looking down when it struck so I did not see exactly where it hit.I was just glad It did not hit me. That would have made this trip even less fun.Lol
    Thanks all Gthornton

    #100076
    rtowe
    Participant
      quote ceyhorn:

      After resetting the Alt switch, did it come back on even momentarily or was the light on immediately? If it did come back on when you were on the ground then I assume the field fuse or circuit breaker were not tripped or blown.

      I had an alternator ghost for a while and would observe different behavior on the ground vs in the air. Turned out to be my voltage regulators. One of my alternators is very weak so the VR’s kept kicking each other off because of the imbalance. I’m in the process of replacing both of them as well as the alternators will all PlanePower components.

      We had a similiar situation in the T303, L ALT annunciator “on”, no circuit breakers tripped, after landing, we pulled the alternator(95A style), had it checked, no problems, re-installed and now working fine. I read the POH and it stated that it is not unusual for the Alternator Control Units(Voltage Regulators) to shut down an alternator if the load on the system is less than 30 Amps(all that work for nothing)…So, for anyone having this problem, check your POH and see if it is similiar…My friend drives a Baron 58TC and has been having this issue for years and we suspect the same issue, he is checking his POH next time he goes flying…

      On another note, we are also considering the Plane Power 150A Alternator(ALT-FLX) conversion that was just released for the belt driven TS/IO-520’s and the IO-470’s. We will have to replace the Voltage Regulators as well and get a field approval because the Crusader T303 is not on the AML. We are considering this because, with electric motor driven Air Conditioning and dual evaporators, we have to taxi around at 1300-1400rpm to keep up the bus voltage due to an 85A load and this is according to the POH. Aparently with the Plane Power 150A Alternators, we will be able to maintain bus voltage at 800rpm…This will be welcome and a relief to my brake pads 😆

      So, if you have electric motor driven Air Conditioning, this might be a good option…

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