I'm a first timer so bear with me. I have a 1989 150 merc V6. Recently I've been experiencing a continuous warning tone from under the console. This has happened several times. Sat. we were running on plane for 10 - 15 min, slowed to idle, and the warning buzzer went off, continuous tone, and wouldn't stop, even after engine was shut down overnight. Temp guage never exceeded 140 F. Cylinder heads are warm but not overly hot. The first time this happened 3 -4 weeks ago, I took it in. They ran it for several hours and found nothing !<br />So today I got a new overheat sensor but before replacing it I disconnected the old one. Still tones (even with engine not running). Disconnected the oil fill sensor and oil flow sensors. Still tones.<br /><br />Disconnected the wire from the warning module to the buzzer, tone stops. touch that wire to the post several times, beeps. Turn off key, reattach the wire to the post and voila, perfect.<br /><br />Now I'm really confused. Warning module failure? Poor contact at the little post ? Anybody got any great ideas?