FX3: intermittent zero amps, spiking oil temp, strobes tripping off

[cavok84]

I believe this issue which has been going on a long time started while still under warranty. Why not ask CubCrafters to warranty replace all three strobes, or at least they should do it in good faith. If not, then determine the vendor for your strobes and ask them for replacements after explaining the issue. I don't know if there is a strobe controller like there is a wig-wag controller, doubt it, but you'd have to review or have Pete tell you the electrical diagram of this system. I hope CubCrafters will help you resolve this in a timely manner.

Yes, that's true. This has been an on-going issue for quite a long time now, well within the warranty period. I think the strobes were either a separate issue or the use of strobes further revealed the problem. This also coincided with the erratic oil temp indications, which turned out not to be a sensor issue, rather a wiring issue on the CC side of things.

AeroLED's or WAT (one in the same now I think) would probably warranty replace or offer advice to test. Just hope you can find resolution and go enjoy that amazing plane @cavok.

Thanks for the information. I'm hopeful as well! I'll keep after it.

The AMM Template will have the nav/strobe/landing schematic. It is pretty much the same for all Carbon Cubs, the only thing that has change slightly is the LL flasher over time with different vendors flashers.

Andy is correct, the connection points are at each nav/strobe, at each wing root and behind the panel near the switches. Also the tail nav has a plug near the data plate inside the tail.

Thanks, Pete. I disconnected the tail strobe, which I thought corrected the issue. But, as I've been flying with my strobes OFF and the problem has continued, would you still recommend testing the strobes?

he characteristics of the EarthX battery make it difficult for me to compare your data with my SBS-J16 data so I hope to receive some data from your aircraft before the problem started.

My plane came with the Earth X. I have all the data on my computer, if you like, I can send some data from shortly after receiving the plane. Or are you wanting data immediately prior to the first signs of trouble?

[cavok84]

Well, yesterday I installed a new alternator, hoping that I could narrow down the problem. After installing it, I was checking over everything but something kept bothering me. I couldn't put my finger on it, until, out of nowhere, the obvious hit me in the face.

The metal mounting plate to which the fuel servo and coils are attached was cracked on all four corners. Completely broken in two places, barely hanging on at one corner, and a small fracture forming on the fourth. This left the forward right side to rattle around freely. While it looks obvious in the pictures, I only noticed it after installing the alternator and preparing to reinstall the lower cowling. I imagine movement of the equipment attached (ignition coils) could've caused some of my issues.

Everything was tight and secure; the plate had no movement that would explain why all four corners would break. While there is a service bulletin regarding the ignition coil brackets cracking, my S/N was not included (it appears I have the new style coils).

Thoughts?

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[Andy]

I doubt this is related to your intermittent charging problem unless the broken bracket has chafed the alternator output cable. An intermittent short of the alternator output wire would cause the problems seen in your data. An intermittent short of the field wire should cause the field CB to trip. Your photos seem to show that the alternator output cable comes close to the fractured upper right coil bracket.

I was aware of the optional SB to change to the new style coil mounting but I had not seen an SI\B on either the original or the new bracket fracturing. I did not see any cracks in my old style bracket when I removed and replaced my fuel servo but I did not look closely at the upper part of the bracket.

[hawgdrvr]

Sorry to hear this @cavok. Not what a new FX-3 owner should be going through. I wonder if CubCrafters could send someone to pick it up and return it to Yakima to get all of this straightened out?

How hard will it be to fix that bracket? Weld or replace? I wonder if a loose alternator caused vibration that did that?

[cavok84]

Sorry to hear this @cavok. Not what a new FX-3 owner should be going through. I wonder if CubCrafters could send someone to pick it up and return it to Yakima to get all of this straightened out?

How hard will it be to fix that bracket? Weld or replace? I wonder if a loose alternator caused vibration that did that?

Yeah, this sucks. If I don't get it fixed by this weekend, I will have missed out both Ozark trips I had planned for this year. The alternator was tight, the bracket was tight, and I'd checked everything that could've caused vibration several times prior to noticing the broken part; nothing was loose or moving around. The alternator doesn't attach to the broken piece, it's mounted to an arm above the fuel servo on the case.

While vibration induced stresses are a part of aviation, I do not think that this is something that reasonably should've failed at 250 hours and a year and a half of ownership. It's also strange that--while two corners are broken all the way through--the other two corners of the metal plate show cracks of varying significance.

I'll call CC tomorrow and see what they have to say, but given the presence of a SB, I think they need to know about this considering I have the updated coil mounts.

Whether or not it had anything to do with the variable amps/voltage, at least I got the alternator swapped for a new one and at least I caught the broken mount.

I doubt this is related to your intermittent charging problem unless the broken bracket has chafed the alternator output cable. An intermittent short of the alternator output wire would cause the problems seen in your data. An intermittent short of the field wire should cause the field CB to trip. Your photos seem to show that the alternator output cable comes close to the fractured upper right coil bracket.

I was aware of the optional SI to change to the new style coil mounting but I had not seen an SI on either the original or the new bracket fracturing. I did not see any cracks in my old style bracket when I removed and replaced my fuel servo but I did not look closely at the upper part of the bracket.

I don't think it was chafing the alt. output wire. I checked it over really well, and the wires, crimpings, and field wire all looked good. Who's to say if the broken plate and attached lines were impacting the output wire under high vibration and g-load, but I didn't see any evidence of it.

[hawgdrvr]

Well, I've joined you in club gremlin. A week ago got a PFD configuration module error on the way back from a fly-in, reseating connector to GDU and so far so good. Yesterday I'm getting erratic RPM readings (+/- 50 RPM) at WOT only, no roughness, gauge issue and also my Aithre CO detector is erratic as well. So I'm Code 3 (grounded) for electrical now until I figure this out. You're not the only one...1 year old FX-3.

[cavok84]

Thanks to everyone on here who helped me get the cub running in time for my weekend trip. It was a great time, couldn't have done it without y'all's help.

https://www.facebook.com/share/v/NKPjHnBs7JSHuLL2/

https://www.facebook.com/share/r/YNaeYjhHPjMc1piK/

Well, I've joined you in club gremlin. A week ago got a PFD configuration module error on the way back from a fly-in, reseating connector to GDU and so far so good. Yesterday I'm getting erratic RPM readings (+/- 50 RPM) at WOT only, no roughness, gauge issue and also my Aithre CO detector is erratic as well. So I'm Code 3 (grounded) for electrical now until I figure this out. You're not the only one...1 year old FX-3.

I'm sorry to hear that. Do you have any ideas?

[hawgdrvr]

I'm glad you got your items squared away. Care to share how you resolved the issues you reported? You had quite a bit going on but I haven't seen anything about how you fixed it.

Earlier this month my RPM gauge is fluctuating rapidly at wide open throttle, does it both in L and R ignitions. Nothing changed, i.e. nothing touched regarding anything behind the panel. No clue why this is happening and how it's been stable up until this point. Data log shows stable in the past and fluctuations now and logged in both, L, and R tests.

[cavok84]

I'm glad you got your items squared away. Care to share how you resolved the issues you reported? You had quite a bit going on but I haven't seen anything about how you fixed it.

Earlier this month my RPM gauge is fluctuating rapidly at wide open throttle, does it both in L and R ignitions. Nothing changed, i.e. nothing touched regarding anything behind the panel. No clue why this is happening and how it's been stable up until this point. Data log shows stable in the past and fluctuations now and logged in both, L, and R tests.

That's very odd, sorry to hear that. Keep us posted as you figure it out.

Any leads?

As for my issues, I replaced the alternator--whereupon I discovered the broken bracket. CubCrafters sent me the replacement part, and an a&p and I replaced the part and checked over everything as well as possible.

So far, the amp/volt. issue hasn't occurred since changing the alternator. I have to admit though that, aside from the 2 hour flight to the Ozarks and 2 hours back, most of my flying was pretty engaging, so I wasn't exactly glued to the panel.

I'll download the data when I get a chance and confirm what I believe to be true, that replacing the alternator corrected the problem. It is also possible that the broken bracket (which secures the ignition coil packs) was causing the issue due to high vibration/movement, but this seems unlikely.

[hawgdrvr]

Great to hear and glad CubCrafters took good care of you, that is always a win for both. Andy is the super star here and he helped me a lot with my issue offline and in the end it was two bad coil packs. Thankfully Lightspeed had them in stock as CubCrafters parts did not and I have a BFR approaching so the timing was not ideal. Now just testing and verifying, making sure no side effects etc.

I need to get to the Ozarks someday, definite cub bucket list item.