A/C comes on sucks too much fuel?

[silencersam]

i have a 2003 sable gs and every time i turn on the "heat windshield defroster" the stupid a/c compressor comes on and i don't know about you but i don't want to spend that much money on gas. So i don't know if this is a problem with the cars electrical or just a bad design. please help

[huminski]

Most, if not all, vehicles with an A/C compressor will run it with the defroster on. The A/C evaporator coil, even if set to hot, will dry out the air coming through the vents which results in a more effective defroster.