That is what I am thinking as it works when you first turn the key to on and doesn't work from the sensor connection.is it possible the ground wire is just for completing the electrical circuit to buzz or beep at KEY ON ? with the 3rd wire (barrel connector) being the real sense wire to be grounded by the heat sensor, vro etc... ?
If it's like the module used in mine, there is a relay inside to generate the "chirp" at power-up.I wasn't sure if there was a separate circuit inside the horn or not because it works from one side but not the other.
Yep that's like mine.If it's like the module used in mine, there is a relay inside to generate the "chirp" at power-up.
Purple (12V) goes to + terminal.
Tan (signal) goes to the other terminal.
Black (Grd) to ground