Data OUT wire for Aera 560 or 660

I pulled the GPS out of the panel to find out why I wasn't hearing the alerts and found it's not connected to anything. It's only connected to power and ground.

The cable has the 2 power wires and also 2 additional thinner wires. Does anyone know what those 2 extra wires are? I was going to open it up and see if I can wire just one of them to Data Out (to connect it to the JPI 830) so I don't have to buy an entire data cable from Garmin just for that 1 wire but if anyone knows or has done it already it'll save me time.

On my Garmin GPSMap 696 the two "extra" wires are RS232 in and out. I don'w remember which is which, but the manual tells.

Cable

Those 2 extra wires are probably for audio out. The various line outputs are covered in the Aera 660 Pilots Guide in Appendix D, which you can download from Garmin Support. It covers both the yoke mount and bare wire mount wiring but apparently not the plug itself, so you may be stuck with buying a new cable!

https://support.garmin.com/en-US/?partNumber=010-01518-00&tab=manuals

Thanks. I think what the previous owner did was cut the cigarette plug off and powered it up directly. Still don't know what those 2 smaller wires are for but it seems like I might have to buy a data cable just for that so I'm now going to have to decide if I install the 560 or the 660 in the panel again and get the cable for that one.