Comments (4)
No. 1-1
Timmmmey2
Timmmmey2

Defroster as in your windshield defroster or your rear defroster? If it's the windshield defroster your ac compressor kicks on. The reason for this is because when the ac lines get cold they draw condensation (fog) off the windshield. Try switching on your ac as if it were summer and see if you have the same results. The ac compressor does put extra load on the engine but it shouldn't be so much that you get no power. Check your freon levels..add if needed.. otherwise it could be a failing compressor. If it's the rear defroster that's electric load in which case would indicate an electrical problem such as a failing alternator or short to ground