'06 SR5 No heat passenger side

Getting ready for winter. Oil/filter change 2 days ago, yesterday back-flushed heater core. Was partly blocked (was minimal, if any, heat from the passenger side centre dash, windshield or floor vents and nothing by the time you reached the window) and I have heat out of the passenger side vents again ... except for the window vents . They still blow ambient temperature. So I think I have/had 2 problems. One was the heater core. Second is perhaps a blend door stuck? If my memory serves me, I think I read that the SR5 has 2 blend doors on a single "rod" operated by a single actuator? I don't have dual climate control, so should be just one actuator, yes? But 2 separate doors (?), and perhaps the one on the passenger side is stuck/broken, and not opening when I ask for an increase in temperature?

Everything on the driver's side works great. Passenger side I now have good heat from the centre dash (though doesn't seem as hot as the drivers side - will pull the meat thermometer out of the cupboard today and recheck), floor and windshield defrost. But no heat at the passenger window vents - either climate or defrost vents. And the windshield defrost is only hot near the centre of the windshield. Farther you go toward the side, the cooler the air gets.

Air flow is fine. Lots of air moving, but no heat. Whatever the ambient temperature is, that's what's coming out. NO heat at all. Not even warm. Could it be that I still have a partially clogged heater core? And that the passenger side of it isn't getting any coolant circulating at all? Better than it was, but still clogged enough that I'm not getting anything toward the right?

Everything I can track down talks about a bad actuator, but that is if they have either no heat, or no a/c on both sides, or dual climate control and only one side affected. I don't hear anything clicking, and since everything works perfectly on the driver's side, I assume the servo is working properly. Today I will be crawling around on the passenger floor to check that actuator.

Any comments, information or suggestions would be greatly appreciated. BTW, I am mechanically inclined, and have the skinned knuckles to show for it, but not a mechanic, and in no position to start pulling apart the centre of the cabin!

 

I'm having the same problem with my 05 I pulled the glove box out and found one of the plastic pieces near the modules unattached so I put it back the was it should have been and now I'm with less heat than before. I'm at my wits end...