Regarding the coolant smell... I agree with BJ. You have a coolant leak in your heater. If it's a large leak, you'll have coolant on your floorboard. It it's a really small leak, the air through the heater may be evaporating it (and carrying the small into the passenger compartment) before it can leak out of the heater assembly.

Regarding the beeping... It may help the super mechanics on this forum if they knew what year and model of vehicle you're talking about!

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.