HVAC problem.....lite up the FnkyChkn Lite

[Cdn_Magnum]

This problem has only happened a couple of times BUT its annoying as all hell at -21c

This is a single zone not dual zone control btw....

- Start up the car and turn the fan on hi and the dial to defrost
- Fan runs on hi just fine... air is blowing to the windshield
- Let vehicle warm up for 5 minutes
- Put vehicle in drive and start driving.
- Under acceleration you can hear the volume of air coming out of the vents deminishing to the point where there is virtually NO air flow coming out of the defroster.
- Move the controls to any position and the same muffled air flow exists.
- Move the controls to Recirculate and the fan blows full force in all the recirculate poistions. But in this mode obviously the interior windows will fog up quickly
- Move the controls back to vent, floor , or defrost and the severally muffled fan sound returns.
- Turn OFF the fan control and then back on again and you can hear the fan blow full force for a second then get muffled again.
- Eventually the system slowly returns back to normal operating conditions.

I have not chaved the HVAC system for codes yet (as per the service manual), but intend to today, though i dont expect any codes to exist.

This is extremely annoying on a cold morning when you cant defrost or heat up the vehicle.

Pete.... any thoughts??!!

[Cdn_Magnum]

OK.... HVAC code 17 is set in the HVAC system...

17–BLEND NOT RESPONDING/STALLED (MTC)

The problem is that all is working well right now..... grrrr

[MikeEast]

Sounds quite similar to the issue I had with the evaporator freezing up, which there was a TSB for, but which didn't do aquat until a sharp tech at BIG-O in Greenville,SC noticed it was a half lb low on refrigerant, which solved all symptoms. Seeing as the defroster uses the AC, might that not part of the answer?

Good luck!

Mike

[fnkychkn]

check posts 9, 13, 17 & 21 of this thread.

i wouldn't worry too much about the HVAC code. it could have been set a while ago and never been cleared. a malfunctioning blend door will not cause these symptoms.

[Mr. iNCREDIBLE]

Along the same lines every so often I get what appears to be freon coming out of my driver side center vent when I'm in a/c mode, doesn't come out of any of the other vents... but you can see something clearly coming out of the vent and it is 10 times colder than any other vent..

no codes though..

[Cdn_Magnum]

check posts 9, 13, 17 & 21 of this thread.

i wouldn't worry too much about the HVAC code. it could have been set a while ago and never been cleared. a malfunctioning blend door will not cause these symptoms.

Pete, when this happens if just sounds like the air flow is completely restricted, like some one has blocked the inlet vent. The recirculate settings work find in all speed settings and at normal volume/sound and if you flip it back to ANY non recirculate position you hear it go completely constricted/muffled..... after a while it all comes back to normal...
Like i said its just a bitch not having an real fan to defrost the windshield till it decides it wants to work properly... its odd because it may start out normal then when i drive thats when it sounds like it gets consticted and stays that way for about 10 minutes or so.

Will take it in again... it did this last year too ... but typical when they had it it was fine.

[MikeEast]

Show them the code and tell them you want a new blend door

Mike

[fnkychkn]

Pete, when this happens if just sounds like the air flow is completely restricted, like some one has blocked the inlet vent. The recirculate settings work find in all speed settings and at normal volume/sound and if you flip it back to ANY non recirculate position you hear it go completely constricted/muffled..... after a while it all comes back to normal...
Like i said its just a bitch not having an real fan to defrost the windshield till it decides it wants to work properly... its odd because it may start out normal then when i drive thats when it sounds like it gets consticted and stays that way for about 10 minutes or so.

Will take it in again... it did this last year too ... but typical when they had it it was fine.

snow accumulates on the fine mesh HVAC inlet screen and starves the fan. once the snow melts, normal airflow resumes.