New Owner Game - What's This??

[ttflyer]

Hey everyone,

I'm a brand new Mooney owner and I have a couple of questions for the group if someone could help!....  This is a 1988 M20J (205) w/ 28v electrical system.

First, what are these two lights (circled in red)?  I think they _may_ be related to the JPI EDM 700 engine monitor but I'm not sure.  I've seen the Amber one come on (very rarely) but I'm not sure what it's trying to tell me.  I think the voltage was reading below 28 volts on the gauge to the left when it happened (and it happened in flight) but it was very brief and quickly went away...  My recollection is that the JPI EDM 700 showed 28 volts, the red "voltage" warning light was NOT flashing, but this amber light was on and the gauge was reading like 25 volts...

Second, the electrical system gauge.  DC VOLTS I understand (except when it's not matching the EDM 700).  %LOAD makes some sense (except it goes to 150% which seems odd).  %ALT makes sense (except how is that different from %LOAD?)...

I did look in the POH and didn't see an explanation of these but might have missed it somewhere.. 

Thanks!

[jaylw314]

Without labels, it's tough to know.  I recall there are annunciator lights for the JPI, but, alternatively, could they be for the G5's?  The AFMS's for the G5 and JPI should be in your POH?

[47U]

Scrutinize your airframe logbook(s).  Start with the entry that installed the JPI 700.  If the lights in question are annunciators related to the JPI, there might be documentation as to their function (hopefully).  Then again, if the installer (of the lights) didn’t take the time to identify their function with a placard on the panel, there might not be anything in the logs.  

You might be dealing with a hangar fairy.  Be on the lookout for other modifications that do not have proper documentation.

Did you buy from the previous owner, or a broker?  One or the other might have the answer, too.

[EricJ]

My airplane has a green "mystery light" in the same spot, and eventually I figured out it was the glide slope capture for the autopilot.    When they're unlabelled like that they can be anything.    You can trace the wires to see if they go to anything sensible, or just wait and see if they ever come on.

[Marauder]

If I’m not mistaken, the green one is for an AIM-7 Sparrow and the yellow one is for an AIM-120 AMRAAM

I would follow the wires back (you might surprised to find no wires connected to them) and see where they go.


Sent from my iPhone using Tapatalk Pro

[carusoam]

Got access to the prior owner?

buying a plane is often a relationship kind of sale…

Dozens of questions that come after the sale, have easy answers…

Things that belong in the plane, may have been left in the old hangar…

Don’t be afraid to dial the phone… 

Often the JPI has blinking lights on the screen… exceeding 2700 rpm by 1rpm can light a warning…

When the JPI is off to the right somewhere… a remote light indicator will be mounted in front of the pilot…

PP thoughts only…

Best regards,

-a-

[tony]

Do you have an MVP-50 installed?

[squeaky.stow]

On 2/25/2022 at 10:57 AM, ttflyer said:

 

I did look in the POH and didn't see an explanation of these but might have missed it somewhere

Welcome to the confusing world of Mooney ownership. You will find a lot of useful knowledge on this forum, but some stuff will be elusive. The POH for the late 1980s is pretty limited in the information it provides. My 252 is very similar to your 205 In many respects, and it originally had at least one of those mystery lights as well. They are not mentioned anywhere in the POH, at least for my model and year. 
On my airplane the amber light was originally the speedbrake light. I don’t know if your 205 has speedbrakes but if you do an internet search of pictures of Mooney panels from that era, many of them have a little amber light placarded as Speed Brake by the top right corner of the old vacuum attitude indicator. In my case it was relocated above the ASI, probably when the Aspen was installed.  I have no idea what the green light is for but @EricJ’s response makes the most sense to me. 
The POH does at least talk about your ammeter/voltmeter but it still pretty vague. In my POH it describes the triple gauge as showing the alternator “output” as a percentage, but it does not say percentage of what. Likewise the bus load is a percentage but shows up to 150%. In my case I have two alternators, so my triple gauge has two alternator output gauges and the loadmeter doubles as a voltmeter at the push of a button.

Interestingly my POH has a schematic diagram that labels each alternator output gauge (the 100% gauges) as “Alternator Output Voltage”. I am pretty sure it is showing amps rather than volts as it behaves exactly like an ammeter should when I add electrical load. So the POH can sometimes add to the mystery rather than solve it. 

Enjoy your new Mooney!

Mark

 

 

[ttflyer]

On 2/26/2022 at 5:39 AM, tony said:

Do you have an MVP-50 installed?

Nope!  JDM-700!

[ttflyer]

Thanks for all the help everyone!  Hopefully the answers will present themselves.  Obviously nothing critical but I like to know my machine!

[jaylw314]

On 2/25/2022 at 6:26 PM, carusoam said:

Got access to the prior owner?

buying a plane is often a relationship kind of sale…

Dozens of questions that come after the sale, have easy answers…

Things that belong in the plane, may have been left in the old hangar…

Don’t be afraid to dial the phone… 

Often the JPI has blinking lights on the screen… exceeding 2700 rpm by 1rpm can light a warning…

When the JPI is off to the right somewhere… a remote light indicator will be mounted in front of the pilot…

PP thoughts only…

Best regards,

-a-

IIRC, the only EDM 700 series that requires the remote annunciator lights is the primary EDM 711 if it is not mounted in front of the pilot (there's a defined area in the installation manual).  I don't think there was another primary 700 series that would have that requirement...

[carusoam]

Thanks Jay!

I have one of the upscale 700 series as well…. Some primary capabilities… all un used in my plane… 

Only wired for CHT/EGT…

 

Another place to look….

Does the charging system have a Zeftronics Voltage controller?

The Zeftronics offers a few LEDs to be remotely mounted in front of the pilot… indicating faults and other outputs…

Easy way to chase those wires… start at the Zeftronics to see if they are wired at the outputs….  
 

PP thoughts only, not a mechanic…

Best regards,

-a-

[1964-M20E]

vacuum high and low warning lights?

 

 

[ttflyer]

11 hours ago, carusoam said:

Thanks Jay!

I have one of the upscale 700 series as well…. Some primary capabilities… all un used in my plane… 

Only wired for CHT/EGT…

 

Another place to look….

Does the charging system have a Zeftronics Voltage controller?

The Zeftronics offers a few LEDs to be remotely mounted in front of the pilot… indicating faults and other outputs…

Easy way to chase those wires… start at the Zeftronics to see if they are wired at the outputs….  
 

PP thoughts only, not a mechanic…

Best regards,

-a-

I'll check that out!  Thanks!

[0TreeLemur]

On 2/28/2022 at 7:08 AM, 1964-M20E said:

vacuum high and low warning lights?

 

 

^^^^ That's my guess too.  Inquiring minds can't wait to find out...

[Yetti]

On 2/28/2022 at 7:08 AM, 1964-M20E said:

vacuum high and low warning lights?

 

 

There should be Mooney panel lights for that.

Unplacarded LED lights for now.

The GPS navigators also have outputs for various LED lights/warnings.

[ttflyer]

I have another question for the group.  And thanks to everyone for your help as I learn this new machine!

In the logbook, we have an entry that the "Bracket Air Filter Due 3/31/2022".  It's a Donaldson PN P130234 and was installed on 3/1/21.  It looks brand new to me and Donaldson says to change it "after three years, five cleanings or 500 flight hours, whichever occurs first."   I'm happy to change it - it's only money.  But I don't want to change it if there is no reason to.  I assume a cleaning with compressed air meets the requirement of "Due"?  When do most Mooney owners replace their filters?

Thanks!

[EricJ]

If it was a Brackett it should be replaced at least annually, according to their instructions, but the Donaldson instructions don't indicate that.    Since you have the Donaldson you can run it much longer, which is one of the benefits of having that filter.

[ttflyer]

17 minutes ago, EricJ said:

If it was a Brackett it should be replaced at least annually, according to their instructions, but the Donaldson instructions don't indicate that.    Since you have the Donaldson you can run it much longer, which is one of the benefits of having that filter.

Gottcha!  so "Brackett" is brand that needs to be changed (at least) every year and Donaldson is a brand that needs to be changed according to Donaldson's service instructions.  I guess the previous mechanic installed a Donaldson but treated it like a Brackett in the logbook for some reason....  I will have our mechanic clean with compressed air and re-install.

Thanks!

[Justin Schmidt]

Don't clean filters with compressed air. For rechargeable filters that is how you damage the filter and will not work properly; can get filter oil going through. Non rechargeable will damage the pleats and you should change anyway,

[EricJ]

1 hour ago, jpschmidt said:

Don't clean filters with compressed air. For rechargeable filters that is how you damage the filter and will not work properly; can get filter oil going through. Non rechargeable will damage the pleats and you should change anyway,

Donaldson filters are paper and the manufacturer instructions allow cleaning with compressed air.   That's a big advantage over the oiled foam Brackett filters, which aren't cleanable.

[Justin Schmidt]

18 hours ago, EricJ said:

Donaldson filters are paper and the manufacturer instructions allow cleaning with compressed air.   That's a big advantage over the oiled foam Brackett filters, which aren't cleanable.

Interesting, I will have to test one. I have never seen a paper filter not be destroyed by using compressed air.

[Guest]

Donaldson filter media is not made of paper, otherwise AD84-26-02 would apply.  They are some form of synthetic media(fibreglass cloth)

Clarence

[ttflyer]

Loving all the info I'm getting here! Thanks everyone.  I did see that the compressed air cleaning was "10 PSI maximum" in the compressor which isn't very much at all...  The thing looks new.  Probably a very light "cleaning" is all it needs!