Recently our 2002 T&C has begun to emit a tone when turning the ignition. It sounds as if it is coming from the speakers, but it is there when the stereo is turned off. It started off fading out within about thirty seconds, but now that it is warmer (heat wave in East PA) it appears after the van has warmed up. Replaced a burnt out headlamp figuring there was some sort of short somewwhere, but this hasn’t fixed it. Anybody else with a similar issue that was fixed???