Hi guys

My car heater doesn't turn on unless I adjust the temperature to 90. It blows out cool air from 60 to 89. Anyone has any idea what is going wrong? The heater is fine before today and I can have the heat adjusted according to the temperature.
Now I only have 1 temperature which is 90.

Thanks.

 

I won't be able to be that insightful but that certainly sounds like something wrong with you controls, not your coolant system or heater core.
You may have to take the dash apart and get at it.