An abutment rib of a first connector portion compresses a coil spring, mounted in a second connector portion. If the connector is released prior to complete and proper electrical connection, the connector portions are moved away from each other to visibly and clearly indicate an incomplete or inadequate connection. When the connector mechanism is properly fitted, retaining projections of lock arms positively engage retaining holes in a hood portion, thereby maintaining the connector portions in a locked and properly fitted, electrically connected condition against the bias of the coil spring urging the abutment rib. Therefore, only when the connectors are properly and completely fitted together, and are prevented from withdrawal, is a proper electrical connection indicated and achieved. The connector mechanism clearly indicates an electrically-connected condition, thereby preventing a half-connected condition.