Do not modify your vehicle in a manner that may affect its handling, stability, or reliability, or install non-genuine Honda parts or accessories that may have a similar effect.
Even minor modifications to vehicle systems can affect overall vehicle performance.
Always make sure all equipment is properly installed and maintained, and do not make any modification to your vehicle or its systems that might cause your vehicle to no longer meet federal, state, province, territory, and local regulations.
Do not modify or attempt to repair any of the electrical components.
Honda Civic Owners Manual. Front Seat Heaters
The ignition switch must be in ON (w*1 to use
the seat heaters
Press the seat heater button:
Once - The HI setting (three indicators on)
Twice - The MID setting (two indicators on)
Three times - The LO setting (one indicator on)
Four times - The OFF setting (no indicators on)
*1: Mode ...