Disconnecting temp sensor has no effect. Buzzer has constant beep when key turned on, but also louder single beep heard when key initially turned on. Louder single beep seems like it would be the system check beep. System check gauge cycles through lights, then all off, but continuous beep continues, even when engine started. Buzzer has only 2 wires, so where would it be getting the ground to sound? Any help appreciated. Thanks.