so i have replaced my heater core and my heat worked fine when it started to get cold out as well as defrost. Then high went out and now medium has gone out. i have also replaced my thermostat. my defrost still works fine and my car warms up just fine and doesnt over heat. i just cant cant thing of anything. could it be a relay or anything?

 

so the blower speeds are going out?

 

There is a resistor pack which is used to control the speed of the heater blower. The selector picks which resistors are needed to get the desired speed. You could have a defective switch, bad wiring, or burned out resistors. If the blower motor is worn, it becomes harder to spin and draws more power, which can cause the resistors to fail.

 

well it also has a 2 year old blower motor as well. its just the speeds that are going out

 

yea, blower motor resistor is bad. i wish i could tell you where it is, but i dont know its exact location

 

yeah i was hoping it wasnt going to be that. i know where it is.