Sounds like the Belt Minder:
PreparationBefore deactivating / activating the belt minder, set the parking brake.Place the gearshift in P (PARK) (automatic transmission) or the NEUTRAL position (manual transmission).Place the ignition switch in the OFF position.Close all the vehicle doors.Unbuckle the driver safety belt.Place the parking lamps/headlamps switch in the OFF position. (If the vehicle is equipped with autolamps, the autolamps must be disabled first.)Deactivating / Activating1) Turn the ignition switch to the RUN position. (Do not start the engine.)2) Wait until the safety belt warning lamp turns off. (approximately one to two minutes)NOTE: Steps 3 through 5 must be completed within 60 seconds or the procedure must be repeated.3) Completely pull and retract the safety belt three times, ending with the safety belt retracted.4) Turn the parklamps/headlamps on then off.5) Completely pull and retract the safety belt three times ending with the safety belt retracted. After this step the safety belt warning lamp will be illuminated for three seconds.6) Within seven seconds of the safety belt warning lamp turning off, completely pull and retract the safety belt. This will enable the belt minder if disabled or disable the belt minder if enabled.The following sequence of events confirm the belt minder is enabled:
The safety belt lamp flashing four times per second for three seconds provides confirmation that the belt minder is disabled.After confirmation, the deactivation/activation procedure is complete.
If there is No Dash Lights associated with the Chime, then Ford Service will have to Scan the Vehicle for Codes. The only other Chime could be the Ignition Key Warning. Ford has had problems with that.
Hi, below is the source of your problem, you will need to get the system tested , it could be a blown out bulb or wiring issue, thanks
The air bag warning chime is activated when the air bag warning indicator is inoperative and an active fault is detected by the restraint control module (RCM). The RCM sends a chime request to the instrument cluster when the ignition switch is in the RUN or START position.