Airstevo

Thanks Marc. I'll do just that. that's great advice. It goes into annual next month and the shop suggested I participate since it's all new to me which I was very happy about. I'll take a bunch of pictures then. I did confirm that it has the LB1B engine and that it is pressurized bedix mags. Thanks you

Thank you! I saved the link. I definitely will be using that as a reference. I appreciate the help

Hi Pete, The airplane is still fairly new to me, so that's why there's a little confusion, well and this is my first time ever trying to figure out all of this kind of thing. I dug into the logbook summaries that the previous owner kept thankfully, made the search much easier and in fact they are the pressurized versions. Yeah lets chat about Yosemite. I'm there a lot since it's so close. I recently did a few flyovers too. amazing place. I'll have a lot of suggestions if you plan on making it down this way. hit me up anytime

Thank you for the reply. It is an LB engine. The former owner had a spreadsheet he created to keep track of maintenance, and he has them listed as bendix s-20, so I'm trusting that for now but I'll keep digging in the logbooks. So far I haven't found anything other than they were checked at the appropriate intervals. Even have gone back to the last engine change, and still haven't found it. The search continues

Hi all, I'm going to be updating my JPI 730 to an 830 and one of the sensors to add is the RPM. Without pulling the cowl off and looking at what exact mag it has, I do know that it's a bendix s-20. I'm assuming it's pressurized. Does this sound right? It seems there are two different sensors based on pressurized vs non. I'm assuming the turbo mooney would have a pressurized mag correct? Thanks for any help Steve

With some more testing with me pretty useless except for running the engine while the a&p measured everything he could get his multimeter on, we(he) decided it was the alternator. That’s been replaced and it’s working fabulously. Really happy to be finally flying it and learning to fly this fun airplane. Thank you all for the different insights and help

should the drive coupler move at all? they said it was moving after they grabbed it with a wrench on it so initially figured that was the problem. so they replaced that already. also added 30% to the part cost which i'm not a fan of. they did check the field voltage and it was reading only slightly less than the alternator output. I don't think they checked the buss connections yet. They did check voltage at the battery and it was showing close to what the voltage on the jpi and aspen efis were showing. I don't know if they systematically have checked each section from the alternator to the the point where the jpi was reading it, but they did a bunch. eventually, the alternator output started dropping to well below 12v and I think thats when they started pointing fingers and deciding it was the alternator now. So now my problem is, they installed a new coupler, that didnt fix it but are charging me $1000 for the part and whatever labor that involved, and still didn't fix the issue. I have the price of the alx-9525B alternator overhaul cost, and it seems about half that of a new one, so if they try to get me again for another 30% for these parts, they've lost a customer. It seems like they like to throw parts and labor at it, until they find it. Frustrating

thank you all for the input. this is a great source. I went out this morning to talk to the mechanic, and he suggested we run it again with him putting his voltmeter on everything to see what was going on. Of course the problem couldn't be replicated, things worked pretty much how they were supposed to, he showed 14 volts at the alternator, but inside on the jpi and aspen efis, both showed the volts moving around a little bit. but charging this time, from about 13.5-14. but moving constantly. he thought that was odd, so shut down, checked circuit breakers, then found some metal shavings on some breakers, tightened up a few things, then ran it again but tried to put as much load on it as possible, running trim, flaps, all lights on, transmitting at the same time. after this started seeing voltage drop below 12, ammeter showed drain. he took voltage at the alternator and confirmed dropping there too, then got to 11 volts as i continued. all of this done with running RPM anywhere from 1200 to 2000. same result. He believes it's the alternator. any other ideas before I pull the trigger on that?

Thank you for the guide. I’ll go through it and see what I can figure out.

Thank you. I will check that stuff. I think they did just throw parts at it. I’m not sure how to handle the cost of their “repair” since it didn’t fix anything

I’ll take a look at those thanks!

Yeah that’s what they did and how much it cost but didn’t change the problem at all. That’s frustrating. It happened immediately so I’m unsure what they saw after they “fixed” it then tested it. they said they tested the voltage regulator, power output of the alternator and all seemed good. Good ok electrical gremlins

Hi, hoping for a little help. Have a new to me k model and have only had a few flights in it. Last flight, any rpm below about 1200 would cause the audio panel to start flashing, radios would cut in and out, and high/low volts would be on. Even powering up to 2000, the audio panel would be steady, but transmitting would still cut out, ammeter showed 0, but charging on the jpi would show 12.5 and sometimes 13 then back down. Mechanic tested everything and said it seemed to be charging, but was possibly some slippage in the alternator drive from the engine so replaced that. Mechanic said it was all fixed and tested and it all works now but when I went to taxi out to fly, it’s all the same issues. I spent 15 minutes trying to put a load on it by running flaps and transmitting and same issues. Low volts stayed in no matter what rpm, radios cutting in and out, and trouble transmitting. Over time I noticed system voltage dropping towards 10. So I went back to the hangar. The alternator was replaced by the last owner a year ago with and overhauled unit. If you know about electrical things, would you mind weighing in on what this could be? A bad battery? Connection from alternator, or just a failing alternator already? Thank you very much.