2008 Mercury Mountaineer-power steering stops working when A/C on
2008 Mercury Mountaineer v6 AWD, ~145k miles. It's been working okay lately, considering. Today, power steering pump stops turning when I turn the wheel while the A/C is on. Steering is normal with A/C off Guessing the compressor is slacking the serpentine belt upstream, although the belt tension looks okay. Replaced serpentine recently. No unusual noises. Tensioner failure? Pump failure? Any other explanations?