my heating system only works on high and in the defrost setting. i understand why it only works in high but why only in defrost? the heat,vent and bi-level do not work but defrost works and if i slide the switch to off it'll shut off. anyone know whats going on? also the heat isnt that warm. i checked with a thermal gun and the temps on the hoses going in and out of the heater core are like 166 on both. what could be the issue there?
thanks
ben
thanks
ben