AdamJD

Is there a way to thoroughly troubleshoot without starting the engine? I watched the Mike Busch 'All About Alternators' from 2016. He recommended to measure from field terminal on alternator, to regulator, to switch, and back to circuit breaker with engine off, stating you should see close to battery voltage through that circuit. He stated that if you have 12v at the field terminal on the alternator, then the circuit is not the issue - meaning a bad alternator. I assume that's because in that case ~12v is flowing through that full circuit to the alternator. Did you do that before you tested the alternator with the engine running? Seems like a quick way to determine if it is the alternator, but I'm definitely no expert on electrical systems. I supposed if the alternator is getting ~12v at the field term with engine off, I can do what you suggest (with really long alligator clips) and measure the out terminal from the alternator when the engine is running to confirm its bad. Anything less than 14v (with a new regulator already installed) would mean the alternator is not doing its job, right? Thanks for your advice!

Thank you! That thread is very informative. I'm going to try and dig in and see what I can find. My problem sounds very similar. I haven't yet changed the alternator. But have a new VR, so I'm pretty sure that is good. I'm hopeful this is a connector / wire issue. Will report back.

Bumping up this old thread. I am having the same issue. Voltage has fluctuated between mid 13s and as low as 12.2 yesterday. It has been doing this for a few months now. I had a new regulator put on yesterday and then flew for 2.5 hours. That didn't fix the issue. I've had two separate mechanics look at and clean connectors. See below. Notice that it started in the low 12s for much of the first hour. Then spiked to the low / mid 13s for the second hour (only change was dropping 500' in altitude as I picked up an IFR flight plan). Then dropped suddenly back to low / mid 12s for the rest of the flight. Again, no real event that would have caused that. Note: Before I dropped the plane off for annual in mid-Feb, it was at 14 every flight. The 1st flight after annual in mid-Mar it was between 13.2 and 13.5. It has degraded since to what you see below. There was no direct work to the electrical system during annual. However, they did some extensive work which required dropping the exhaust system. Could moving things around have caused anything? Interested in anyone else's experience or thoughts. Thanks!

Another thread that shows this in action:

Yeah. I watched the IAS swing about 5-10kts - my TAS on the 275 was slowly fluctuating between 135-145kts. I usually see ~143 at that altitude and config. I *think* I can download the flight data from the 275, but haven't tried that yet. But I could see it on both the analog ASI and the 275.

Interesting observation. I had my gfc500 installed in Nov. However, they finished the installation just as the autotrim service alert came out. So I flew it for several months without autotrim. I didn't notice any significant oscillation issues. Autopilot was still enabled, but I had to trim by hand. I recently had the software update completed. I picked up the plane last week and have flown two 2.5+ hour cross country flights since having the autotrim turned on. Now, the plane oscillates slightly in cruise. Both 2.5+ hour flights had +/- 7kt airspeed (and groundspeed) osciallations. BEFORE autotrim was enabled AFTER autotrim was enabled

These worked great for the torpedo lights in my 67F. They dim fine for my needs. Not a large range between dim and bright, but again, they work for my needs. -> https://www.superbrightleds.com/led-light-bulbs-universal-finder/miniature-and-subminiature-bulbs/67-led-light-bulb-12-smd-led-tower-ba15s-base+color-Cool~6500K+packamt-2-Pack I put this in my dome light. Also works well. -> https://www.superbrightleds.com/led-light-bulbs-universal-finder/miniature-and-subminiature-bulbs/67-led-light-bulb-12-smd-led-tower-ba15s-base+color-Natural~4000K+packamt-Single

The elevator must be removed and the paint must be stripped for the inspection. It doesn't say that the weight itself has to be removed. But it's still a pretty labor intensive job for inspecting the weights. "1.3. If the balance weight is determined to be a hybrid weight 430018-1, and initial inspection shows no sign of cracking or chipping, Continue to STEP 2 for further action." "STEP 2 - Detailed Inspection of 430018-1 weights:" "2.0 - REMOVING ELEVATOR WITH 430018-1 WEIGHTS" "2.3. Strip paint from balance weight per applicable Service and Maintenance Manual Section XI" "2.1.0 BALANCE ELEVATOR With 430018- 1 Weights (Complete and Painted)" "STEP 3 - Replacing 430018-1 Hybrid Weights with 430016-7 Lead Balance Weights:" So Step 3 is the actual replacement if the weights are found to be cracked or corroded.

So stupid question from a new Mooney owner. How do we tell if we have the affected counter weights? We can't tell by serial number? My F is at the avionics shop, so I can't just go out and look.

Ugh. Didn't realize we were going to have to wait longer for the fix when driven by the 275s.

It's a shame we can't disable the auto-trim in the AP without disabling the electric trim on the yoke. I'd love to still use the manual electric trim.

Any word on this? I was lucky enough to pick up my GFC 500 install on 11/22, the day after the alert. So I too have my AP, but not the auto trim, as it was disabled in the 275. But my right arm is getting tired...

Received the final verdict. According to the installer, you cannot display more than 1 Misc Field with the GFC500 installed. Must need the space for annunciations. So I will use Tom's workaround. In 3-1 and Basic mode, there certainly is screen space for those small fields. I hope they fix this minor annoyance - after they fix the runaway trim.

That is a great workaround. I'm going to do that too. Thank you!

But you still could keep 2 displayed at the same time? I really want TAS and wind vectors. I can get the other 2 elsewhere. But I can't get 2 to display at one time. Based on your experience, I suspect that maybe the GFC500 annunciations are reserved for the bottom of the 275 and that's why the Misc Fields can't use that space. That's the one difference between his install and mine. I have a GFC500 and he doesn't.

Update - just s Good idea. I'm going to see if he's comfortable going into his sw config settings. I just spoke with Garmin support. They were nice but not overly helpful. They said it's a 'software configuration' and my installer will have to talk with the Field Engineer. I went through the available software configurations when I changed the display to 3-1 to remove heading last night. I could not find an option to increase the number of Misc Fields allowed at a time in the sw config. I've sent an email with screen shots to my installer as well to get his thoughts.

I have that already set to TAS. But I can't find a way to do all 4 at once. See the picture in the original post from my friend's 275. He has all 4 displayed at the same time. I can display either TAS, GS, OAT *OR* Wind Vectors. I changed mine to 3-1 last night and successfully removed the heading ribbon. But I still can ONLY select ONE of the 4 Misc Fields at a time. I really want TAS and Wind Vectors, as I get GS and OAT from other areas (430, iPad, GTX345, etc).

Ok. That helped me with some answers. 1. Per installation manual section 4.2.25.1, you can select from 3 different ADI display modes, one without tapes (Basic), one with just airspeed and altitude tapes (3-In-1) and one with airspeed, altitude and heading (4-In-1). So my friend's config in the photo above is the 3-In-1. 2. Per the pilot's guide, you can only add a Misc Field. However, in the 4-In-1 mode, you can only select TAS as the Misc Field. It doesn't show other options. However, in the 3-In-1 mode, you apparently can add TAS, GS, OAT and wind vectors because the heading tape is gone. So that explains why I didn't see the option for anything but TAS in mine as it was in 4-In-1 mode. 3. For brightness, in the installation manual section 4.2.26, you can select photocell or lighting bus and then configure the photocell. I will report back when I get a chance to configure all of these.

+1 for Google. I've been using duckduckgo.com for searching. It does NOT come up in that search engine. When I said I "googled", I was using the verb. So I went to Google.com and viola, you are correct, it came up first from piperowner.org. Thanks! Digging in now...

I couldn't find it. I googled for a while. Found the maintenance manual, which doesn't address my issue. Found versions of the installation manual which only included the first 14 pages. Can't seem to find the full install manual. Seems that's pretty secretive. Will call the installer next week.

Thanks David. Removing the heading tape and adding those additional fields must be an installer setting. I'll go back through the menu settings and find how to get rid of the CDI. It's interesting that heading tape would default to ON if you have an HSI installed as well. There's duplicate heading / course info within inches of each other. You would think the heading tape would default to OFF but would pop on if the HSI were to fail (or be turned off). Maybe that's how it works with the installer config. Need to do some digging but the manual isn't overly descriptive on this. RoundTwo - yes, some installs tie to the dimming bus. But mine doesn't change with my panel dimmer switch. Post lights and backlit avionics work fine - dimming up and down. ADI doesn't budge with the dimmer switch. We never discussed this at install, so I need to follow up with the shop on this. All I know is that it was very very bright at night until I manually dimmed on the ADI. And then the next flight in the daylight, the ADI was very dim until I manually brightened. Minor annoyance. I'll ask about both when I go to the installer for the sw upgrade for the auto trim issue. Hopefully soon.

Pirep. I love my electric step. Installer put in an up/down switch. The step automatically comes down when the master goes off. But it is slooooow. So I put "Step Down" on my clear of runway checklist. Step switch is right by the avionics switch, so it's hard to forget to put the step up on start up. For what it's worth, I think some of my suction issues were from the step. The installer showed me the pneumatic boot for the step and it was all torn from wear. I wouldn't be surprised if the steps wasn't even retracting before. Anyway, I love the electric step and am glad I didn't just have it welded down and I'm glad I didn't remove it like some folks do. My wife wouldn't appreciate a missing step.

Hi all, Just installed two GI275s for ADI and HSI, along with the GFC500. While I am absolutely loving the upgrade from steam gauges, I do have a few issues I'm hoping someone can help with. 1) The ADI is very cluttered. At the bottom it has the heading ribbon, GPS / ENR annunciation, heading deviation indicator, etc. However, my HSI has all of that same information right below. While I appreciate the redundancy, I really want to get rid of the heading / course info from the ADI. A friend who has the same model installed had this done by the shop. See attached for his 275 ADI vs. mine. He also has wind vectors, temps and groundspeed. I want all of that to show in mine without the heading. Is there some way I can setup mine like his without having to go back to the shop? 2) The ADI is super bright at night. I thought maybe they wired it into my panel dimmer, but turning that makes no difference. The photocell seems to not do anything. I did manually reduce the brightness for my night flight. Then when I went to fly during the day, I had to manually turn the brightness back up. Is there something I'm doing wrong that the photocell seems to not be working? Thanks for any insights you can provide! Adam

I second that question. Those rear seats look great. Mine are headrest-less. And no matter how hard I've tried, I can't find a headrest that fits. For the OP, my 67F is the same. Reclining front and rear seats. Front are on a wheel with three positions. That wheel is wearing out on both seats, so I'm in search of a solution. One time my seat slipped into recline on takeoff. So now I'm hyper aware on takeoff and try not to put pressure on my seat. But I would like to find or repair the mechanism. +1 for the rear seats being 'easily' removable. I agree that verbal abuse is required to get them out though.

My M20F has been in the avionics shop for the past 5 weeks for an upgrade, which included replacement of the vacuum step with an electric step from http://flightenhancements.com/auto-step.html. I pick it up this Friday, so I'll let you know how it turns out. My Britain system was full of leaks, including the boot for the step. So it is a timely replacement. The shop put in a dedicated switch for the step - Up and Down.