Heater Troubleshooting, how hard should the blower blow? Options

[cassidy_bolger]

I know it is a bit early for this converstaion, but I am working on getting my weak defrosting solved before soggy fall arrives here in the Pacific Northwest. I have taken a crack at this today, but am now stuck. If anyone has ideas for me I will appreciate it!

The situation is this:
With the engine running and warm and the heater lever on (up) I get heat and defrost on both sides of the cabin But, it is more powerful and hotter on the passenger side. When I turn on the in-dash fresh air blower and set everything to defrost (all levers to the right), it actually overpowers the heat on the drivers side and that air is cool/warm. The pass. side is still fairly hot, however, and that side stays nice and clear in the winter.

So today I am troubleshooting:
-Adjusted flapper box cables to make sure they can open all the way - made no difference.
-With engine OFF and heat lever on, there is not flow at all coming out of the downstream side of flapper boxes. Heater blower is running.
-With engine RUNNING, flow and temp are the same whether the blower is running or not (with heat lever off I manually opened them to test )
-The heater blower has only one duct and it is connected to driver's side only. But that is wierd, since driver's side is weaker. So, I pulled that duct to test flow of heater blower - it blows but a bit weak. Should this thing be stonger? It sure makes a lot of noise for what it puts out.

Now I am stuck:
-Am I missing something about this system should work?
-Is my driver's side heat exchanger clogged?
-Or is my blower motor too anemic to do any good?

Attached are some pics in case any of you can spot an oddity.