I have an 02 4Runner with manual climate control. I initially thought I had a problem with my AC system because of the intermittent cooling. Now that the temps have dropped to the 30s, the heat is doing the same thing. It works intermittently.
After the engine is warmed up, the heat may work fine and then suddenly start blowing cool air. If I cycle the temp control knob from hot to cool and back a couple of times it will normally blow warm air again. This is exactly the same thing that was happening with the air conditioning. It would blow cold air and then start blowing hot air out. If I cycled the temp control knob it eventually blows cold air again.
I am guessing the controller itself is going bad but wanted to get everyone’s thoughts on it before buying a replacement. Is there anything else that could cause the problem? If I replaced the controller, is there a good alternative other than oem?
After the engine is warmed up, the heat may work fine and then suddenly start blowing cool air. If I cycle the temp control knob from hot to cool and back a couple of times it will normally blow warm air again. This is exactly the same thing that was happening with the air conditioning. It would blow cold air and then start blowing hot air out. If I cycled the temp control knob it eventually blows cold air again.
I am guessing the controller itself is going bad but wanted to get everyone’s thoughts on it before buying a replacement. Is there anything else that could cause the problem? If I replaced the controller, is there a good alternative other than oem?