First time question so I will keep the maintenance updated after I get the issue resolved.
I recently purchased a 06 V8 4x4 for the wifey. Low miles, well cared for and really stoked to get it.
The heater is not working. The auto temp system recognizes the that the temp is not increasing so it tries to compensate by increasing air flow. Basically, not a blower issue or a recognition issue, rather it is just not blowing hot air.The A/C works great with no issues. I do not hear anything like a door opening or closing when I switch to heat.
Took it to a Toyota dealer today and the tech told me he couldn't figure out what was wrong and it would be $1150 to get to the evaporator coil to further diagnose. He spent about 15 minutes on the vehicle before coming to that conclusion. Yes I nearly choked. This sound a little odd to anyone?
I am aware that getting to the evaporator is a large job, but would the AC still be running if it were an issue specific to the evaporator?
BIg Mahalos for any help.

Is this a function ONLY when using "Auto" function? Or if you manually set the vehicle to A/C Off + Blower High + High Temperature do you get hot air?

We need to determine first and foremost how exactly are operating your HVAC system.

I am not get hot air using either option.

Good question though.

How is the coolant level and/or have you had issues with overheating? You also mentioned blend-air doors which could be an issue, there's some limited testing that can be done, but it can be borderline inconclusive.

No issues with overheating and or coolant level.

I know its not an easy diagnostic and definitely not throwing the techs opinion out of the door but though it worth at least doing some research before dropping that kind of change on a heater in summer.

I hear absolutely nothing when I switch from cool to heat. Should I be hearing something like you mentioned, possibly an actuator or a motor on the blend door? Could it be a fuse for that matter that I am unaware of? I checked the fuses that where heat related but they all checked out fine. Im not saying it is impossible for the heater to go out but not exactly common. The heater core is hot on both sides.

If it was an evaporator issue wouldn't there be a problem with both heating and cooling?

Head scratcher for sure. Thanks for the help BW.

Well you probably won't hear the blend air door. If the inlet and outlet of the heater core are good and there's no cooling systems, the next thing to check is the electrical system for the blend air doors. But again, that may or may not be easy (haven't done it on a 4Runner yet), followed by possibly tearing the dash apart to get the HVAC box out.