Honda Civic warning light flashing with alarm sound and engine not starting, possible fuse issue after trailer wire installation on Honda Civic

Some Honda Civic owners report experiencing issues with a flashing warning light and alarm sound accompanied by an engine that won't start after installing trailer wires, potentially indicating a fuse-related problem. These owners often find it necessary to check the fuse box for the trailer fuse, inspecting it for damage and replacing it if needed. Additionally, verifying power at the 7-pin plug on the rear of the vehicle can help rule out car wiring issues. Some owners have resolved the problem by disconnecting the ground wire, which may suggest a grounding issue. Others note that starting the engine too quickly can trigger warning lights and alarms, so waiting for the dashboard to fully initialize before attempting to start the engine may help. Furthermore, checking fuse 23 and related components is recommended for those experiencing multiple sensor-related issues, such as with keyless entry and power door locks.