Car loses power steering and power brakes in rain or thru puddles on 2002 Hyundai Sonata

Problem occurs regularly even going through shallow water. VERY SCARY - Sudden loss of steering and brakes for about 30 seconds then will be OK until next puddle is hit or with a heavy rain. Car had spark plugs replaced 35000 ago. Belts look tight and firm. Car runs firm and smooth in normal weather.

Asked by for the 2002 Hyundai Sonata