2003 Ford F150 XLT 4.2 V6 automatic 200k miles. My A/C compressor comes on when i put the heat on. It will come on with the defroster which i know is normal but will also come on when i put the setting to "panel/floor" is that normal for the compressor to run while on that setting? It goes off when i put it to just "floor" or just "panel" and comes back on with defroster mix or just defroster or AC, the heat blows hot on all settings and the AC works fine.