The heater has never worked 100% correctly for me. It got to the point a couple of years ago that I could only have all heat or no heat, but nothing in between. Then it got to the point where there was no heat, just outside air. The secondary coolant pump was changed back then and it seemed to kind of work for awhile.
This last winter it started acting up again- no middle range, just all or no heat. Dealership didn't seem to have any solid solutions, but I decided to have them change the secondary coolant pump again and this time I had them also change the 4 actuators- 2 intake mix doors and 2 mode doors.They did say that a control assembly board (pn 27500-9CH1B) was bad and replaced that too. Now, for example, when I set the heat to 74 degrees, it'll go to that temperature just fine, but it will only hold for a minute or 2 and then the warm air starts cooling off. So I turn it up a few more degrees and it goes to that new temp, but starts to slip again. It'll do this all the way up until the heat is at max and then it will hold. So again, it really is all or no heat. This is all on the manual setting, I've never used the auto setting for heating and cooling.
Dealership doesn't seem to have any other ideas. They suggested I leave car with them so they can duplicate the problem, but it feels like a shot in the dark from them.
Any help appreciated. Thanks in advance.