heater fan blows weakly

[65TerrorCuda]

So I replaced the burned out original blower motor on my 65 Barracuda(was burned out when I got the car) and it's never blown hard at all since. In comparison to my brother's 64 Dart, it's less than half as powerful. High on my car is like low in his!
The only test I've done is to run the blower fan on high for a few minutes(I'm assuming this bypasses the resistors), heat set to cool, to see if the resistors are still getting hot. OUCH! I reached back there and touched the area where the resistors are and got immediately scorched.
Shouldn't this place(top of the resistors) be cool with the fan set to high? It had to be 200 degrees. I get all 3 speeds (plus off) but they're just so weak.

 

[RedFish]

Those resistors get extrememly hot even with air blowing across them.
That is normal . If I had to guess why the air flow is weak.. blower running backward or vent door not opening properly.

 

[65TerrorCuda]

Initially I had the polarity backwards, now that was really weak. And the door works properly.
Maybe this replacement blower motor doesn't have the rpm it needs. Crappy

 

[Longgone]

I thought the same thing as RedFish, that the polarity was reversed but it sounds like you`ve got that worked out. Try bypassing the resistor all together and see what you get.

 

[Slappy]

Check actual voltage on high with a meter and post it. It should bypass the resistor on high. Check your ground integrity [corrosion]