Hi,
I have a 79 camaro with A/C and a brand new blower motor and blades yet I am getting a very low volume of air coming out of my vents.

I have tested the blower motor prior to installation and it blows very well and it is getting a full 12V. I have checked over all the duct work and there is no leaks. I did notice there are 2 vents with flaps on the passenger side, one under the windshield wiper and one under the dash.

When I turned on the blower with the lower vent closed, a large amount of air was blown out of the upper vent. When I close the upper vent the air stops coming out of all vents almost completely. When I open the lower vent with the top close it starts coming out of the vents but it is still very weak.

FYI:
I dont think the vacuum lines are working and my Blower switch only works on high.

Does anyone have a diagram of how the air is supposed to flow through the ducts or any idea why Im not getting much air output? It just doesnt seem like I should be loosing all this air through the vents.

Thanks

 

Man my 1994 is doing the same thing! Brand new everything in the AC and it doesn't seem anywhere near powerful enough... I'm not sure about this. I was thinking that maybe I could put a bigger blower motor in my car and get some more power out of it. Let me know how you go about fixing it. Not that it'll be the same as my car. lol

 

Is your condensation leaking from the evap can properly?

this may help? http://www.nastyz28.com/tech/aircond.html

 

that's a good idea about the water in the box.
also on modles with a/c , when the evaporator ( rad inside ) starts to leak , oil will come out with the freon and cause dust to stick and gradually block air flow.
or the is just grit that has gotten there some how.
some times your luky on models that with the blower motor removed you can see if the is stuff blocking the evaporator. but a second geeration camaro ... no sure what is best way,

 

By Evap Can are you talking about the drier?
When it gets cold it does have condensation dripping from it.

If the evaporator core gets clogged how would this effect the volume of air created by the blower motor? It's just a fan right?

 

If the blower seems weak, you may want to consider cleaning out the gunk accumulated on the outside of the heater core and evaporator core. They can get pretty dirty, and being that the blower must force all the air through them, dirty cores can cut down the air flow considerably. You may also consider cleaning all electrical connections to the blower motor, including the speed control resistor. Dirty connections=high resistance=low voltage=low blower speed.

 

So it could be obstructions on the OUTSIDE of the heater & evaporator core?

I cleaned both of them out INTERNALLY last week prior to hooking up my new drier and compressor. I do get really cold air coming out, it just doesn't blow worth a damn.

It does seem kinda strange to me that I only get the HIGH speed from my blower motor control switch and that none of the vacuum lines seemed to be opening or closing any flaps in the duct work.

My buddies were wondering about some type of obstruction in the air flow as well...

It doesn't seem right that a very hard air flow would be coming out of the outer vent or the lower vent.

As for electric, I am getting a consistent 12V from the pos wire...

Thanks

 

ok , soo then you need to be sure the vacuum from the engine is making to inside the car. do you hear a hissing sound under the dash only when the engine is running?

 

Dude I dont hear any hissing sound! Thats why I wanted to see a diagram on how the air was supposed to flow through the system.

I mean why would air be pushing out of vents outside the car ??

 

have fun with that.