Hi Coded9, The issue could possibly be a faulty Blower motor Resistor. You can find it on our site here: https://www.fcpeuro.com/products/volvo-blower-motor-resistor-s60-s80-v70-xc70-xc90-8693262 This is located at the blower motor and control the speed of the blower. If you have any additional ques...