If any electrical devices are not working, turn the ignition switch to LOCK 0*1 and check to see if any applicable fuse is blown.
Fuses
Engine Compartment Fuse BoxHonda Civic Owners Manual. Synchronized Mode
You can set the temperature synchronously for the driver’s side and the
passenger’s
side in synchronized mode.
1. Press the SYNC button.
The system switches to synchronized mode.
2. Adjust the temperature using the driver’s side temperature control dial.
Press the SYNC button ...