No heat in front good heating in the back. I have a problem getting heat for my defroster and heater in the front, AC works OK but I don't get any heat. The backseat heater works great. I have notice that the recirculation button works intermittently, however after driving for an extended period of time the heater in the front does start to work and so does the recirculation bottom. I've changed the thermostat, checked the valve on the firewall, fluid levels are good, purged for vapor lock, charged the AC, fuses are good, no leaks in the system, NOW What? Is it a sensor? I so where is it? or is it the Heater Control in the Dash? Any ideas? Its a 2001 4 Runner SR5. Please help and Thank you in advance.

I have a 2017 SR5 and I sometimes have issues with heat and cooling. I think for me it might be a blend door actuator that might be causing the issue. If I set it on blowing towards face and feet, it's almost like nothing really happening until you turn it up to max. However, if I just place it to just face it would blow full force. I really don't feel like taking apart the dash like I had to with my Jeep Liberty to get to those fricken things.

It might be something to look into.

Grunt3327