I have a 1997 Toyota Camry and recently the air flow from the heater has become stuck on the front vents. Regardless of what setting I turn the switch to (defrost, floor, etc.) it doesn’t switch from the vents. It seemed to happen about the same time the thermostat died, which I had to replace (successfully I think).
I looked under the hood for a vacuum hose that might be disconnected (guessing) and under the dash for a wire that might have come loose or disconnected, but to no avail. I am guessing that some part on the heater has stopped working and needs replaced, but I haven’t a clue as to which one…hopefully one that won’t require pulling the dash off (that’s a pain).
If I understand your post correctly, heat continues to come out the vents even when you change the vent configuration with the switch? If that’s true, then it isn’t some part of the heater that’s broken, it’s simply the vent doors that divert the airflow. I don’t think these are vacuum operated. I believe they’re mechanically operated via solenoids.
Stop by the Toyota dealer and ask the parts guy for an “exploded view” drawing of the duct system and one of the dash that includes the glovebox. That’ll make working on it much easier. I’m going to take a wild guess and say that the airflow controllers, the solenoid operated valves that direct the air, are going to be behind the glovebox. The heater core and blower are back there, so I’m guessing that the air controls are too. It would seem logical from a manufacturing standpoint.
Understand that I’m making a few guesses here. I’m thinking that the Camry had gone to the pushbutton controls by '97 (like my 2005 Scion has) rather than the totally mechanical slide switch like in my '91. Correct me if I’m wrong.
Does your Camry have automatic controls or manual levers? Automatic controls with a dial or buttons have electrical actuators to move the flow control flaps. Levers use a cable system. I’m assuming you have the automatic controls, and the electrical actuator for the vent control has gone bad. Toyota doesn’t use vacuum for the vent controls.
If I remember, if your Camry has manual temp control you have rotary knobs and a completely cable operated system. The first thing I would do is give the mode knob a firm pull to remove it from the control panel and look at the back of the knob to see if the part that slides over the control shaft has broken.
If that isn’t the problem it shouldn’t be too hard for someone with mechanical ability to move the controls while lying under the dash and looking at the cables and figuring out what’s wrong.
Yes, it is a rotary dial switch. I will check the knob in the morning, but everything feels normal when I turn it. I will stop by a Toyota dealership, ask about the electrical actuator and see what they can tell me about a diagram and where things are located and then I will see if I can see (if they are cables) them move.