Wifes AC is not cooling efficiently and power steering fan doesn't turn on and it's 93 degrees plus here. I thought the PS fan was suppose to come on when AC turns on? Anyway I noticed the high speed fan doesn't come on at all. Pulled connector to radiator fan and tested 12v from battery to low speed and high speed pins. Low speed comes on, high speed does not. Could it be that the low speed fan resistor is bad? I replaced it like 3 or 4 years ago. If not this, what would prevent no high speed fan?