Air Flow

[tepes]

having an issue with the amount of air coming from the vents, the blower motor sounds nice and loud, but there is little pressure from the vents themselves regardless of any of the pushbutton vent settings i choose.

example, if i choose floor it switches to the floor but has low volume of air moving, if i choose defrost, it moves to defrost but has a low volume of air moving....

what comes to mind in a situation like this.

thanks in advance
Tim

1991 Cutlass Supreme

edit: hope this is in the right spot.

[pocket-rocket]

Moved for better topic traffic

How does the blower motor sound? Does it sound normal or does it sound like it's spinning slow or is it growling at you?

[bszopi]

To expand on Jon's question, when changing the speed of the blower (1 to 2, 2 to 3, etc.), can you hear a change in sound showing that the blower is in fact changing speeds?

[Azrael]

If you live in a dusty environment (gravel/dirt roads or near concrete plant) then it could be possible that the fan may be caked with dust or the vent where air is drawn into the cabin is partially clogged. The heater core could also be clogged up but that would only affect airflow when full-heat is selected.

[tepes]

no the blower motor doesnt sound to me to be making any abnormal sounds, yes it does change speeds as a higher fan speed is selected,.

any pointers on where air is drawn in from? i feel its a blockage as the vehicle did sit on a farm for several years, who knows maybe a mouse nest eh...

[jman093]

no the blower motor doesnt sound to me to be making any abnormal sounds, yes it does change speeds as a higher fan speed is selected,.

any pointers on where air is drawn in from? i feel its a blockage as the vehicle did sit on a farm for several years, who knows maybe a mouse nest eh...

Might also check if mode is working properly or that it isn't constantly just blowing a lot of the air out of the defroster vents. This often happens if there is a vacuum leak somewhere on w-bodies.

[95SleeperAcheiva]

I believe...the air intake from inside the car is behind and up from the glove box. But, your outside air intake, which is where is should be drawing first is a screened over (or should be) vent by the passenger side wipers. Do you have electronic HVAC or manual?
All the HVAC door actuators are vacuum controlled, make sure your vacuum lines under the hood don't have any leaks, a vacuum leak won't allow enough vacuum to operate the actuators and then you get air flow going out the HVAC intake rather then through your vents. check the vacuum reservoir too. A good way to help look for vacuum leaks is to start the car, and spray either carb clean or starting fluid around all vacuum lines and ports, don't forget to spray behind and around brake master cylinder, the booster is vacuum controlled so it can be a vacuum leak problem. Be careful! If you have a miss/bad spark plug wires this stuff can ignite! While your spraying down listen to the idle rpm of the motor. If it changes pitch by going up or down, you found your leak! This is basics.

ON-BOARD DIAGNOSTIC MODE

air conditioning is equipped with an on-board diagnostic feature which allows the Heater And A/C Control Assembly to detect certain system faults. The diagnostic feature can also be used to display certain data parameters. If the Heater And A/C Control Assembly detects a fault in the system, the C0 or F0 annunciator will flash during the first two minutes of vehicle operation.

Entry into the diagnostic mode is gained by depressing the "OUTS TEMP" and BI-LEV buttons at the same time. Once the diagnostic mode is entered, any trouble codes stored will be displayed. If none are present, 00 will be displayed.

If the WARM button is depressed after the trouble codes have been displayed, the data mode will be entered. The information available in the data mode is displayed in units used by the computer which may not be of use in observing the system. To exit the diagnostic mode, press any mode button.

Refer to the illustration for a list of the Trouble Codes and their meanings.

NOTE: A two digit trouble code indicates the fault is present now. A three digit trouble code indicates an intermittent fault.

This will work if you have electronic HVAC.



Pics courtesy of ALLDATA

[95SleeperAcheiva]

ehh...i forgot.

OH YA! #'s 10 and 11 are air intake