GRT Avionics

Good Afternoon Jeff,

Thanks for calling me back yesterday and talking thru the CO2 Guardian Remote Units (353P) operation and capabilities with the GRT HXr’s.

After looking into the issue of not hearing the corresponding audio alert tones when resetting I now have found it, but it brought with it another issue (of course it did! Lol).

I wired the 353P to my MFD (I have two HXr’s a PFD and MFD).

I noticed today in reviewing my wiring schematics and interconnect diagrams that I never wired (never needed) to wire the audio outputs from the MFD to my audio panel.

I DO have the PFD wired to it (Pin 24 to Audio Panel - GMA345) and the corresponding audio ground.

Q1: Does the interconnect between the PFD and MFD transfer audio as well (I think not?)
Q2: I am OUT of “Alert Audo Hi and Lo’s on my GMA345… do I have any options? I saw Garmin says not to splice them as it can cause issues…

*Note: Remember, this is to get audio warning and when I reset/test with my lighted push button test switch I would then get the flashing of the light (2x) in addition to audio tones.

Thanks in advance,

Gary

Typically only one display is wired to the audio system. Most data is shared between displays so they will produce their own audio for the same issues. If you wired both you would get the same alarms played on both screens at about the same time. The displays don't share audio signals or files and one display can't make another display produce audio.

If you are out of unswitched inputs then your only option is a switched input like maybe a spare NAV2 or AUX2 but you have to keep it on to hear it. Splicing audio outputs together is complicated and a simple splice with resistors lowers the volume.

Hi Jeff, thanks for the info... to clarify;

My NAV's are all used, however what appears to be AUX2's are available (*IF* these are the ones you are referring to).

When you say I have to "keep it on to hear it" are you simply saying the Audio Panel has to be powered on (if yes, then understood).

So, see attached Pinout... my Pins 7 and 8 are available... would these work per your reply or am I missing the boat (plane) on this one?
Thanks!

Gary

I mean they are switched inputs controlled by a button on the panel so you have to make sure the input is turned on with the button, and some of those inputs may be temporarily muted by other audio. Looks like pins 7 and 8 should work for Aux2.

Thanks Jeff,

When you say "Some of those are switched inputs controlled by a button on the panel" do you mean the physical reset button that I put in the panel FOR the 353P?

Meaning if I push that reset I would then hear audio if wired to pins 6 and 7 or would I have to turn something else on as well (audio panel and 353P will already be on in this case)?

Thanks,

Gary

No. Look at the buttons on the front of the GMA345 audio panel. There is a button labelled "AUX2" that acts as a toggle switch that controls whether or not you hear anything from AUX2. You can push that to toggle any audio coming from AUX2. If AUX2 is not selected/enabled by that button you will not hear anything from AUX2. You would have to check that AUX2 is on and avoid accidentally pressing it.