I would appreciate any help with this problem.

Low to no heat. Top inlet heater hose to heater core is hot, bottom hose is cool. Air mix valve has full travel both directions. I suspect the heater core.

Checked my dealership $300 to R & R heater core. So....

Disconnect battery.
Disconnect heater hoses.
Remove glove box & panel below glove box.
Remove Programmer sheild, air mix link now accessable.
Remove air mix link, rotate towards firewall.
Release Programmer, 2 screws, remove vacuum line, lower to floor.
Remove heater core cover, 2 screws, left & below glove box.
Remove the heater core, 2 screws, cover floor with rags for potential anti-freeze spill when core is removed.

Autozone has cores in stock, $42.

Reverse procedure to install. If you have not flushed system in past 1-2 years now would be a good time to insure core is not contaminated with crap from system.

This is a doable job. Don't panic, just step through it.
Hope this helps someone in the future,

Joe in Arkansas

Have you tried to reverse flush the core with a garden hose ?

Yes, reversed flushed with hose and also used CLR to try to break loose any crud in the core. Very little, if any, difference.

It's fairly easy to replace. Have you changed it out yet?

Yes, I swapped out the core. Put everything back together, added 1/2 gallon of anti-freeze and I now have great heat!