You need new HVAC controls. The knob is broken. Just something that happens eventually with the 3rd gen. I just solved this problem. My dial suddenly did not influence the temperature anymore and I was stuck on hot. You have a limited model, and I have the 2002 SR5 model, so I can’t tell you the part number because the year and model matters. But there are companies that will fix yours if you send it in, or you can buy a refurbished one off eBay like I did. Toyota time with Timmy did a short video on this. Moreover, I suspect that your hvac air door actuator was disconnected by the previous owner, since they were manually adjusting it from the engine bay. The actuator is the little motor that is connected to the wire that runs through the firewall to the heater valve you just changed. It’s located on the passenger side floor area. It’s very easy to access. You would have to make sure it’s still there and connected to that wire and connected to its wiring harness. It’s what your knob is directly communicating with.
You need new HVAC controls. The knob is broken. Just something that happens eventually with the 3rd gen. I just solved this problem. My dial suddenly did not influence the temperature anymore and I was stuck on hot. You have a limited model, and I have the 2002 SR5 model, so I can’t tell you the part number because the year and model matters. But there are companies that will fix yours if you send it in, or you can buy a refurbished one off eBay like I did. Toyota time with Timmy did a short video on this.
Moreover, I suspect that your hvac air door actuator was disconnected by the previous owner, since they were manually adjusting it from the engine bay. The actuator is the little motor that is connected to the wire that runs through the firewall to the heater valve you just changed. It’s located on the passenger side floor area. It’s very easy to access. You would have to make sure it’s still there and connected to that wire and connected to its wiring harness. It’s what your knob is directly communicating with.
Did that fix your issue? Also having the same issue. If it did would you mind sharing the part number for the replacement piece?