GMA 240 Wiring Questions

Noah · #1 10-27-2010, 07:18 PM

Please forgive my ignorance. The pre-wired harness for my Garmin GMA-240 has several leads I'm not sure what to do with.

The 3 wire "music" will go to a stereo input jack on the panel for an IPOD. I think I should use a 3.5mm jack - is this the best option? Is this also good for a cell phone or should I be using a mono input for cellphone? Or a different size jack? Are these typically separate?

There are two 2-wire "audio-aux" inputs that I'm not sure what to do with (?)

There is a two-wire "unswitched audio" input that I'm not sure what to do with. I think that the pre-wired harness includes unswitched audio inputs for the GTX-330 and AFS units for traffic warnings and other AFS audio inputs. Is there anything I should be thinking about doing with these other inputs??

And finally, I have XM (WXWorx) weather, but AFS does not presently support music. I think I read that they are going to include it someday, maybe I should be pre-wiring for that? Any thoughts?

Thanks in advance.

schristo@mac.com · #2 10-27-2010, 08:33 PM

Hi Noah, I wired my 240 from scratch without a harness and only populated what I was actually using but I can offer a few thoughts... There are 2 dedicated music inputs; both can be wired directly to devices but input number 1 is also fed from the front panel and it trumps anything hardwired. I have xm music directly on input 2 and a 3.5mm plug tucked in the mapbox for music input 1... practically speaking it is just as easy to plug in directly to the panel input though. The panel input also manages the phone connection but you can wire up a dedicated input through the harness; again likely easier to just use the front panel input when needed.

The aux inputs are for general use and can be switched on or off from the front panel... you can use them where you might wire in alarms where you want to be able to turn the alarm off, or for vor, ndb, marker beacon, whatever...

The unswitched audio is likely referring to one of the three alarm inputs... the only problem with these is that you can't silence them from the audio panel... no problem if you can silence them from the source though.

I would defiantly plan for an xm radio connection and would anticipate using music input 2.

Noah · #3 10-28-2010, 10:27 AM

Thanks Stephen,

I would think a cellphone input jack would be mono; therefore 2 wires vice a stereo input with 3 wires? Or can a stereo jack be used with a cell phone?

mburch · #4 10-28-2010, 10:29 AM

I believe the GMA 240 has a 2.5mm cellphone jack right on its front panel. If it were my airplane, I'd just use that...

mcb

schristo@mac.com · #5 10-28-2010, 10:49 AM

Quote:

Originally Posted by Noah

Thanks Stephen,

I would think a cellphone input jack would be mono; therefore 2 wires vice a stereo input with 3 wires? Or can a stereo jack be used with a cell phone?

Hi Noah,

The cell connection is mono. The front input has circuitry to facilitate dual use as both a stereo music input and a mono phone (with mic) input... the panel phone button engages the auto detection for a phone input. The is also a jumper override to force phone source if the button is pressed.

The front panel input is a 2.5 mm plug but the unit comes with a 2.5 to 3.5 stereo cord.

jchang10 · #6 01-15-2012, 12:20 PM

When I use the cable that came with the GMA-240, it works sort of with my cell phone (android phone). The telephone works. However, if i play an mp3 file on the smartphone, none of the music buttons on the audio panel seem to be effective. I am assuming the audio panel sees the phone and ignores all the music functions.

However, if i plug the same cord into a dedicated mp3 player for instance, i get no sounds. Thus, something in the wiring may be crossed?

Any ideas? Do I have a different 2.5 to 3.5 mm cable?

Jae

Quote:

Originally Posted by schristo@mac.com

Hi Noah,

The cell connection is mono. The front input has circuitry to facilitate dual use as both a stereo music input and a mono phone (with mic) input... the panel phone button engages the auto detection for a phone input. The is also a jumper override to force phone source if the button is pressed.

The front panel input is a 2.5 mm plug but the unit comes with a 2.5 to 3.5 stereo cord.

CMW · #7 04-17-2013, 01:22 AM

Jae,

Did you ever get an answer to your problem? I have the same issue with the front jack. If I plug an ipad into the music 1 input it works fine.

Chris

Brantel · #8 04-17-2013, 02:22 AM

Take a look at page B-3 in the installation manual. The bottom of the page and the notes are very important to proper operation.

humptybump · #9 04-17-2013, 04:16 AM

This may not be for everyone but, if you have and plan to use a smartphone with your GMAIL-240, you cand do the following:

Music L+R+C combines with Phone S+M+C
(left right common) and (speaker mic common)

Tie L & S together and tie C+C together.

You now have four wires: L&S, R, C, and M

(this assumes the smartphone uses the 4-wire 3.5mm plug that is now common on phones that are stereo)

I mounded a 4 conductor 3.5mm jack on my panel. I can use an iPhone for music. The music mutes for alerts, radio traffic etc. Without any changes, I could use the phone for ground pops, weather, or an emergency.

My alerts from GPS and EFIS go to the alerts 1&2.