Climate Control Issues 83 300SD

[porscheman87]

I have replaced the blower motor and now can only get heat on low setting, turn fan to High or Auto and the air cools down. Have tried unplugging monovalve still no heat on high or auto, any Ideas.........

[PatricdeBoer]

Maybe your monovalve is only allowing enough coolant flow to warm the smaller volume of air that is passing through the core when the fan is on low. I would pull the monovalve and see if it is opening and closing fully.