As I bump up the heat, there is no noticeable difference in the temperature coming from the vents. I have the fans set manually to high to keep them consistent. When I get the temperature control on the dash to 'Hi', the heat comes on full blast. Anything less than that you really can't feel any difference.
I looked that heater controller valve. It seems to be working. The cable will move it back and forth and I can move it easily by hand. It goes from completely closed, to completely open, but no where in between. But, it doesn't seem to make a difference. When its fully open, it doesn't give me heat. I even disconnected the cable and manually opened the valve completely up. You'd think that would be full heat regardless of what is set on the dash. But it doesn't make a difference. Only when I click it to high (the valve doesn't move any more) does the heat come on. So I think I can rule out the cable binding up, the HCV being bad and the relay. I haven't flushed the coolant in a while, but there is enough. And since it IS possible to get heat at some point, I figure that's not the issue.

To summarize: heater control valve fully open, temp set to 85, no heat. heater control valve in same position (fully open), temp set to 'hi', lots of heat.

There has to be another part that I'm missing that controls the amount of heat coming into the car. Does anyone have any ideas?

Thanks for all the great information on this site. I've already learned a ton. Too bad we haven't uncovered the problem yet.

 

Read the following thread along with the two referenced threads in there.
https://acurazine.com/forums/problem...rectly-918506/

I think there is a temp blend door as well that has to open for the heat to work.

 

it actually sounds like the blower motor resistor they are about 35-50$ retail.

I just want to make sure I am reading this correctly.
Your fans dont blow air accept at full blast?
If you leave it on full blast and turn the temp to LO, will cold air come out?
With the AC on LO does the fan still only blow the same way?
If the answer to these questions are all yes then its definitely the Blower Resistor.

If I read it wrong and its an actual problem with the ac blend door then thats different and ignore everything u just read

 

Read this post too. It's exactly what my TL was doing before I fixed it.

"https://acurazine.com/forums/problem...-thing-899287/"