Marauder Posted August 26, 2016 Report Share Posted August 26, 2016 https://vimeo.com/180363010 Here is a quick video of the issue in action from my flight this morning. Full throttle had just leveled off from the climb. Sent from my iPhone using Tapatalk Don't know what the cutoff is for overvoltage on the charge, but your JPI is fluctuating between 14.1 V and 14.3 V. Seems to be in rhythm with the overvoltage light. Perhaps a simple turning down of the voltage on the charge? Sent from my iPad using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted August 27, 2016 Report Share Posted August 27, 2016 Great video. Way to help other people help you! i've not seen any needles move like that under normal conditions. the value on the analog needle is not going to be reliable information. The momentum of the needle and instrument parts is too large. Something is making it sweep through extremes... What causes the fluctuation is probably well known by the voltage controller guys or somebody with strong mechanic skills. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted August 27, 2016 Author Report Share Posted August 27, 2016 Frustrating thing is that it doesn't happen at all on the ground and intermittently in the air. Battery starts the engine strong and is kept steady at 12.8-12.9v. Most of the flight the voltage is steady at 14v on the JPI and then jumps as in the video to 14.1-14.3. Plan of action right now is to replace the master per the Don Maxwell article since I attempted cleaning the contacts with no luck. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted August 27, 2016 Report Share Posted August 27, 2016 Frustrating thing is that it doesn't happen at all on the ground and intermittently in the air. Battery starts the engine strong and is kept steady at 12.8-12.9v. Most of the flight the voltage is steady at 14v on the JPI and then jumps as in the video to 14.1-14.3. Plan of action right now is to replace the master per the Don Maxwell article since I attempted cleaning the contacts with no luck. Sent from my iPhone using Tapatalk What is the sampling rate of JPI? Default is 6 secs, I recommend setting it the minimum of 2 secs. Because of this JPI won't show transient spikes very well. Looks to me like alternator is cutting out. I would check all connections and if in doubt clean contacts and retighten. If it was the master I would think avionics would show errors when they lose power and the ammeter wouldn't be fluctuating to the negative side. It could also be internal to the voltage regulator. 1 Quote Link to comment Share on other sites More sharing options...
mike_elliott Posted August 27, 2016 Report Share Posted August 27, 2016 2 hours ago, teejayevans said: What is the sampling rate of JPI? Default is 6 secs, I recommend setting it the minimum of 2 secs. Because of this JPI won't show transient spikes very well. Looks to me like alternator is cutting out. I would check all connections and if in doubt clean contacts and retighten. If it was the master I would think avionics would show errors when they lose power and the ammeter wouldn't be fluctuating to the negative side. It could also be internal to the voltage regulator. Also clean the ammeter itself, and just for grins, check the integrity of the field wire between the alt and vr. Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted August 27, 2016 Author Report Share Posted August 27, 2016 Good suggestions guys. Plan on continuing to diagnose over the weekend. Battery is confirmed good so that is one item off of the list. Also the alternator is charging and keeping the battery charged. Took a 1.5 hr flight this morning 12.7V before the flight and landed at 12.8V after. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted August 27, 2016 Author Report Share Posted August 27, 2016 Also the new starter is a night and day difference over the old one. It is so much easier to start now. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Smiles201 Posted August 28, 2016 Report Share Posted August 28, 2016 I have had this problem, needle going back and forth, voltage fluctuating, turned out to be a poor connection between master and alternator. Check voltage at every juncture. You may have a slight voltage loss at some point which in effect turns the alternator off and on very rapidly when the engine is running. Master could also be bad. Lots of other threads about this. Quote Link to comment Share on other sites More sharing options...
skykrawler Posted September 4, 2016 Report Share Posted September 4, 2016 For the wagging ammeter It is still possible that the master switch is the culprit. You say you have cleaned the contacts but I think you mean the lugs. The internal contacts can accumulate resistance over time and the solution might be to replace the switch. Since you have recently replaced the master relay (assume it is good) and you say you hear it audibly engage there must be a connection problem somewhere between the master relay and the bus or somewhere in the ground path to the air frame. If the master relay is dropping out it seems like a possible problem with the ground circuit back to the relay which includes the master switch. The master switch provides a ground to the master relay to turn on. Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted September 12, 2016 Author Report Share Posted September 12, 2016 Quick update on what has happened since I originally posted: - Figured out that the batter/master solenoid I replaced with the Sky-Tech was defective after talking to skytec. Apparently it was a known issue which has since been fixed. They sent me a new one free of charge and I now have only a .1V drop across the solenoid. - I replaced the starter. Bad solenoid on the starter. I have a 149-NL core if anyone is interested. - I replaced the master switch. I took a 2.5hr flight this morning to South Florida and the wag did not occur on the flight. Fingers crossed this issue is now solved. Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted September 12, 2016 Author Report Share Posted September 12, 2016 When multiple issues are present simultaneously it sure makes troubleshooting a bear! Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 12, 2016 Report Share Posted September 12, 2016 Great follow-up, Drew! Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted March 10, 2017 Author Report Share Posted March 10, 2017 Quick update. Since this post I have replaced my Voltage Regulator and Alternator and completely solved all electrical noise and problems. I am flying IFR a lot and use my plane for business and felt it was cheap insurance. The plane power alternator is amazing! I have had zero issues with the new starter and have around 90 hours on it since replacing. Plane starts and runs beautifully. The master solenoid was the only one I replaced and it has not given any problems. I do know they had an issue with a batch that were sold but my replacement from them was sent at no charge and has worked great. Sent from my iPhone using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
MooneyBob Posted March 10, 2017 Report Share Posted March 10, 2017 53 minutes ago, Drew_Wagner said: Quick update. Since this post I have replaced my Voltage Regulator and Alternator and completely solved all electrical noise and problems. I am flying IFR a lot and use my plane for business and felt it was cheap insurance. The plane power alternator is amazing! I have had zero issues with the new starter and have around 90 hours on it since replacing. Plane starts and runs beautifully. The master solenoid was the only one I replaced and it has not given any problems. I do know they had an issue with a batch that were sold but my replacement from them was sent at no charge and has worked great. Sent from my iPhone using Tapatalk What Voltage regulator do you use now? I bought new one ( R1224) from PlanePower together with alternator but then realized it is not good for M20J. Quote Link to comment Share on other sites More sharing options...
Drew_Wagner Posted March 10, 2017 Author Report Share Posted March 10, 2017 I found a yellow tag original on eBay Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 11, 2017 Report Share Posted March 11, 2017 Nice Pirep, Drew. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
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