Sport Pilot Talk

I had low voltage inside of the cabin and sometimes the radio would not transmit at low rpm so I cleaned up my grounding terminal inside and  forward of the firewall of my REMOS G3. Now the voltage is back to normal.   and I can transmit at all rpms. However I must have bumped a wire someplace under the panel and now the intercom doesn't work  . Also the co-pilot head set does not work but both PTTs on the sticks are are OK.

Does anyone have a suggestion where to start my trouble shooting (witch hunt)? There are no obvious unconnected grounds or other wires. Its a PM501 intercom.

Some intercoms have an isolation feature. Is it possible that isolation got selected on the intercom without you realizing it?

When I press the onoff button on the intercom (its a push button feature of the squelch knob) I hear a click and hiss on both headsets but nothing else. The copilot headset does hear or talk to the pilot and does not transmit but the copilot ptt button on the stick causes the SL40 to transmit. The pilot side headset works fine.

Toggle switch up or down?

The "iso" toggle switch position (up or down) doesn't make any difference.