91 Sunbird....air/heat not blowing hard enough

Hi i'm looking for answers if anyone can help. Our 91 sunbird w/air doesn't put out the air or heat through the vents as powerful as it used too, we've replaced the blower motor and it works, the speed of the fan works when you change from low to high and all the switches from defrost to multi level etc all operate, it sounds good blowing but very little comes through the vents......any response appreciated.

Ahmayen

Reply to
Ahmayzen
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Make sure that you don't have a leaky vacuum acuator some where. Also make sure that the baffles are moving freeling inside the dash.

Tim

Reply to
Tim Schoell

"Ahmayzen" wrote

You probably have a plugged evaporator core. Pretty common problem on a lot of GM products. Does your A/C still blow cold air? If so, you can probably just clean the fins of the evap core and you will have air flow again. You can do this on this model by removing the blower motor resistor pack, and loosening the nuts that hold the heater/a/c box to the firewall on the engine side. You can move that case out a bit and see the evap fins from there. Engine shampoo and a garden hose cleans them off quite well.

Ian

Reply to
shiden_kai

Did you replace the fan motor with a GM replacement?, if not check to make sure the motor is going in the right direction I have seen many aftermarket fan motors installed so as to cause the fan to turn backwards

Reply to
jhones.family

Check to see if your heating/cooling coils in the heater box aren't clogged.......mine was bigtime, I yanked the housing off, washed down with Gunk Foamy engine brite and its like a new car............the 2 lower nuts (10mm) are a bitch, be patient........... Doc Zort

Reply to
BushmanBro

That worked on the wife's Beretta - (after I dismantled half the dash looking for a blockage) - evap was black as crap.

I ended up using a Pot Brush from the dollar store, some soap and water and a hose. Pulled the blower out and reached in there. Took out the resistor pack and stuck the hose in there. Had the wife using the shop vac and a tarp inside the car. Worked ok - the brush worked the crud loose without bending the fins on the evap.

I would have removed the plenum, but it looks impossible to get the bottom bolts out with the steering rack in - which is a major PITA to change on this car - even with the engine out.

If all the controls seem to work, there's just hardly any force, the evap is probably just plugged. I think it's mold that grows on there... yum. :)

Ray

Reply to
ray

I'd like to say thanks to you all for helping out! It was that evaporator core thing with all the fins in the firewall behind the housing, it was a huge difference in air flow, it suprises me how much crap gets in there but then again if it happens only once every 10 years that's not so bad!

Thanks again group!

Ahmayzen

Reply to
Ahmayzen

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