Help: No heat but the AC is fine

Hey guys, I'm on a road trip in my 2015 Tundra and we have lost all heat. The blower works fine, and so does the AC. Just no heat. Ambient air only when the heat is on. Thankfully we're heading to Texas, but it's not too warm there, either. No heat at the rear vents. It's an SR5 so manual dial controls, no fancy temperature control. Anyone have any issues like this? Of course it's just out of warranty

250 miles to go and running out of sunshine, getting a bit chilly!

 

Welcome from NC! Wish I could help but I can only think of checking fuses...

 

Thanks! A bit more info...it seemed to be very sensitive earlier today when it was working and one "click" of the temperature dial would cause a rather large change in temperature. I'm guessing I'll be digging after the temp control unit-we heard a clunk earlier when messing with the temp control so I image there's a loose mechanical connection in the unit.

 

Keep an eye on you truck water temperature and check the water in the radiator. Sounds like the thermostat gone bad or water pump went out.

 

This ^^^. Check and report back.

 

Truck temps are good. Temp gauge is in the normal spot.
Just stopped for gas and checked the fuse. All looked good. No change after shutting the truck off and restarting. Looks like we'll just get home and I'll look at it in the morning. Thankfully the cold front hasn't hit yet

 

45K miles.

 

Welcome from Northeast Connecticut. Check your anti freeze

 

HVAC filter is good. No shortage of air blowing, just cold. Anti freeze is good, too.

Got home late last night after driving over 1100 miles from Ohio to Texas. The last 300 had no heat whatsoever. It was 34 degrees when we got home...we were popsicles

I'm going to pull the blend door actuator later today and see what I find.

 

Update: I checked the actuators and both seem to be working normally, the gears seem fine as well. I checked the coolant hoses coming into the cab behind the dash and the are nice and hot with truck warmed up. So now I'm trying to remove the blend door actuator assembly. Has anyone actually removed it? I dont see how I can do this even if I pull the entire dash apart. I can get to 3 of the 4 screws holding the assembly down, but the last one is directly behind a welded metal support. Of course whith three of the four screws removed there is enough play for various gears and parts to fall out...behind the carpet and shift console until they hit metal. Getting frustrated over this thing...I'm getting dejavue of my old Dodge

 

Don't start blaming Toyota just yet. I had a pen fall down the duct work in a Ford and the same thing happened. It was an older model and the HVAC door and heater core were very accessible without dash removal. Dodges and Jeeps are well known for blend door problems and it is not a cheap fix.

 

On my old Dodge, the dashboard disintegrated so it was easy access

I read on another forum about just drilling a hole through the metal support for the 4th screw, so I'll try that and and least get the assembly out where I can work on it.

 

I take that the truck is still under warranty?

 

So I drilled an access hole and got to the temp control box. I can manually manipulate the arm for the temp control and no change. Feels like something let loose in there, no resistance.

I normally do all my own work, but about out of options on this one.

 

And of course the truck is 6 months out of warranty. I've had 6 Toyotas in a row and they seem to be steadily growing down in quality. How they deal with this will determine if I have a 7th Toyota when I replace my wife's Camry later this year.

 

Just got a call from the dealer. They said there is a failure in the HVAC box, which I had confirmed as well. Not a serviceable item. $3000 for them to replace. Basically have to strip it down to the firewall and evacuate the coolant and AC.

A $42k truck 6 months and 8000 miles out of warranty...they told me to call Toyota customer care. Ugh, not a good start to 2019. And we specifically stuck with the lower trim package so there would be less electronics to fail.