Airflow thru vents

[yennchi45]

Hey guys hoping someone can help me out with this one. I posted this a few years ago and got no response so I focused on some other things for awhile and now I’m back to it. Problem is that the airflow thru the vents is not very much even on the high fan speed setting. Passenger side has even less air flow than the driver side. All duct work seems to be fine is there anything else I should check?

 

[383_StealthRam]

Have a look at the following post, assuming your blower motor is working fine (electrically) at all the speeds through the resistors, and the high blower relay, then you should go through the vacuum and air flow troubleshooting steps to determine what might be wrong.

Note, there's also the possibility that you have a lot of build up dirt on the the heater core, and/or evaporator core that is hindering air flow from blower motor from getting to the inside HVAC box. Also, you could have a lot of air leaking from dried out or missing foam seals around the plastic ductwork behind the dash. I have this issue on mine with the AC on, I can reach my hand behind the radio pod and feel a lot of air leaking that should be coming out the dash vents. I have to get that old foam sealing replaced one of these days.

Credit to Ribbedroof for posting the service manual pages to help troubleshoot.

MALIBU Post in thread 'Vacuum/Defrost'

Mar 16, 2024

Here are the pertinent pages from the 88 shop manual, which is pretty much the same system as all G bodies OTHER THAN the automatic A/C system found in higher option carlines (I think Buick and Olds...never seen one in real life)

• Ribbedroof

• 

 

[yennchi45]

Have a look at the following post, assuming your blower motor is working fine (electrically) at all the speeds through the resistors, and the high blower relay, then you should go through the vacuum and air flow troubleshooting steps to determine what might be wrong.

Note, there's also the possibility that you have a lot of build up dirt on the the heater core, and/or evaporator core that is hindering air flow from blower motor from getting to the inside HVAC box. Also, you could have a lot of air leaking from dried out or missing foam seals around the plastic ductwork behind the dash. I have this issue on mine with the AC on, I can reach my hand behind the radio pod and feel a lot of air leaking that should be coming out the dash vents. I have to get that old foam sealing replaced one of these days.

Credit to Ribbedroof for posting the service manual pages to help troubleshoot.

MALIBU Post in thread 'Vacuum/Defrost'

Mar 16, 2024

Here are the pertinent pages from the 88 shop manual, which is pretty much the same system as all G bodies OTHER THAN the automatic A/C system found in higher option carlines (I think Buick and Olds...never seen one in real life)

• Ribbedroof

• 

Thanks for that info looks like I should probably get ready to pull the dash out and really take a good look at the foam seals. Been trying to avoid pulling it out until I was ready to replace it, but because of funds I have been putting it off. May just pull it out and do one of those dash caps for now!