GM340 / CDM750: Mute audio PA

[BlackForest]

Hello everybody

I have two GM340 here, which I intend to use in an Ham- UHF- repeater setup. As such, it is not neccessary to have the speakers on the units working. I am aware about the possibility to open up the control heads and just disconnect the speakers.
However, as it might help with troubleshooting someday, I'd like to keep them connected.
Now I wonder about the function 'Mute Audio PA' in the CPS GP I/O menue: From my understanding programming a pin on the accy- connector with 'Mute Audio PA' as low active would switch of the audio amp when tied directly to ground.
I would have just tried it out, however, I'm scared to brick the radio :|
If so, it is handy to mute/unmute the audio just by flicking a switch in the gnd- line. And, in the best case, save a couple of mA on the repeater site.

Best regards,
Markus