A momentary loss of power steering can occur when the AC or defroster is on during high humidity conditions. This is due to condensation from the evaporator draining onto the serpentine belt. To fix the problem, a spout on the AC evaporator drain and a new serpentine belt should be installed. Some vehicles may need a revised serpentine belt tensioner.
Problem Reports » Momentary Loss of Power Steering Due to Water From the Evaporator Drain on the Serpentine Belt