A/C blower not blowing hard

[crawlink5]

78 Blazer. Got the A/C going today. Needed to put electric fan on because flex fan was not moving air. Used a 98 Mercury Grand Marquis 2 speed fan.

have recently removed fender and evap box and cleaned it out, cleaned coils, and resealed box putting it back on. It was not that bad.

Motor is about 5 yrs old but with just a few hours run time for heating.

Cold air is coming out. The air is blowing hardest in the far driver side then as going to pass side it gets less. On max setting and high switch no air is coming out of heater box or at windshield. Its just not blowing hard especially on pass side. It SOUNDS like it is blowing hard but it is not.

Cold or heat baffle moves freely. High low switch works correctly and is new. motor relay is new. I did not change the resistor coil things in the evap housing. Showing 12.5 volts in factory guage, have 140 amp alt and two batteries.

Is there a super duty jet-rated blower motor I can get from somewhere?

Any ideas on what to check next?is there a connection somewhere that could be giving resistance because its old?

Thanks

 

[Fordum]

If the motor sounds like its is running hard, it probably is. Most likely one of the doors is stuck.
You have a couple, that direct the air to different vents. Some are vacuum actuated, but in yours, I think its all cables.
Most likely the little connector where the cable hooks onto the door is broken off and the door is shut trapping all the air inside.

There should be someone here who is familiar with your model and can give a clue as to which door it is.
You might be able to see it under the dash with a flashlight, or maybe if you pull the control panel off the dash and trace the cables through the hole you will see one disconnected.

 

[77 casa grande]

Check the door at the top of the passenger side kick panel. It has a large vacuum operated diaphram valve and will affect air flow if its hung up.It controls were inlet air is drawn from. It is open when a/c is set to max to recirculate the cabin air and closed to draw fresh outside air from the cowl vents. The slide bar on the temperture control only moves the plenum door between the heater and evap cores.

 

[crawlink5]

I have changed out the vent door to a manual vent. If I close it the air flow drops.

I'm wondering if I have a poor quality fan motor.

In a Blazer as you all know you need a good air flow because of a lot of space to cool.