OK call me dumb but ....

I heard that using the front defroster turns on the A/C compressor automatically on most vehicles. Is this true and why????

Just to get this straight but the front defroster thing is the vent that blows air on the front windshield right?

I'll probably get flamed for being dumb but oh well

Yeah, some do use the A/C when on defrost. The A/C dries the air comming into the cabin and helps get rid of frost (on the inside) faster.

oh ok thanx much