On-vehicle connector unit

An on-vehicle connector unit to be attached to a partition wall of a vehicle that separates a cabin from a vehicle body, and to interconnect a connector of an electronic device in the cabin with a harness connector in the vehicle body, the on-vehicle connector unit comprising:

• a case including a tubular body and a front plate located at a front end of the tubular body, the front plate having an opening;
• a circuit board housed in an internal space of the tubular body;
• an interface connector mounted on the circuit board to face the cabin from the opening of the front plate, the interface connector being for use in connection to the connector of the electronic device;
• a rear cover blocking a rear end of the tubular body;
• and
• an internal connector held by the rear cover, the internal connector being for use in connection to the harness connector, wherein
• the on-vehicle connector unit has a first portion to be located in the vehicle body, the first portion being waterproof to prevent water from entering the internal space of the tubular body,
• the on-vehicle connector unit has a second portion to be located in the cabin, the second portion being non-waterproof to allow water to enter the internal space of the tubular body,
• the front plate has a drain hole communicating with the internal space of the tubular body, the drain hole being configured to drain water from the internal space of the tubular body, and
• the drain hole faces in a same direction as the opening of the front plate faces.