97 4runner 2.7 heater problems

[972.7runner]

first of all thanks for the add.
I just bought a 97 2.7 E3RZ 5spd, and the heater only blows luke warm air. i have since replaced the heater control valve,thermostat, coolant flush and flushed the heater core out. the hoses that go in and out of the firewall to the thermostat are hot. i have also checked under the passenger side and everything seems to be hooked up and operating correctly. i am completely stumped at this point, any suggestions. it also has rear heat that has been disconnected and plugged off, which at some point i will reconnect.

 

[gwt500]

same problem here

did what you did and got same result. Open the circulator on heater control panel. Don't know if this is it. I haven't got mine all back together yet to try it. This opens a door on the blower motor housing. The blower motor picks up air via this door. If I understand it correctly. This is the air that passes through the heater core and out the vents. No air- no heat. The owners manual says the circulation should be open. The blower motor works right? The motor speeds- low-m1-m2 and high work through a ballast type resistor about 3" long. This is located beneath the blower motor. If this goes you will lose 1 or more of the speeds. There is also a relay in this circuit that can fail. It's in the front and above (outside) the BM. Finally there is another door operated by cable. It directs the heat out the vents. If this don't open, no heat. Let me know what you find out. good luck

 

[gwt500]

Found my heater problem

I'm the same guy that answered before. It is the "air mix control damper." It is operated by the slide control with the red/blue wave. Same control operates the heater hose valve on the firewall. 2 cables. Anyway the damper (door actually) in the hot mode opens to direct air from the blower through the heater core. The door closes in the cold mode (AC) redirecting the air around the core (bypasses it). With mine the damper wasn't closing. Even though the cable is connected. If I close the damper by hand. The control will open it. But it doesn't close it. No air was going over the heater core and so no heat. To see it. You got to pull open the bottom half of the AC evaporator box. You got 2 or 3 small bolts and 2 metal clips that need to be removed. Then you can create an opening by pulling down the bottom half. It won't come off. But you be able to see and open/close that damper with ya hand. Operate the control with your left hand and see if it opens/closes. The cable can be adj on top. But it looks like a *****. What I may do is just close the damper and disconnect the cable. I don't think my AC works anyway, never use it. The control will still operate the heater hose valve. Even if you don't have AC. Still may be a damper. You'll have to remove the bottom plastic piece under the glove compartment. Then look to see if there is a black cable operated by the control. Good luck.