Heating/AC system question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

longhorn396 · 08-19-2011, 03:14 PM

Hey guys my 94 pontiac grand am wont switch setting from vent to defrost or from vent to floor. Idk how or even where to begin looking for why the vent doors arent moveing or closing. if i can fix it easily im gonna keep the car if not im gonna sell it when i get another. Any help appriciated!!!!

**VetteVet** · 08-19-2011, 10:38 PM

This is a common problem and the usual cause is the blend door motor actuator. It has a plastic gear inside that strips out and won't move the door. You can replace it if you're handy but they cost between $150 and $200. You might get one for less from GM Parts direct on line. Google blend door motor for more info.

longhorn396 · 08-20-2011, 08:00 AM

What part of the dash is it in?

**VetteVet** · 08-20-2011, 12:44 PM

It varies by vehicle but most are in the center not far from from the heater core.
I would go to the auto parts store and pic up a Haynes manual for the car. it will tell you a lot more about remove and replace and a lot of other stuff than we could ever cover here. They run about $20 and well worth it. It might be the climate control switch too, which would be easier and cheaper to fix.

longhorn396 · 08-20-2011, 01:06 PM

If its just stripped can u still hear it make noise cause i dont hear it doing anything when i do???

**VetteVet** · 08-20-2011, 02:33 PM

Well let me say that I am not familiar with the mechanism that drives your door. It may be the old style vacuum can or it might be a newer gear drive . If you look under the dash and see some saucer shaped cans with vacuum lines to them then you have the old style. If you can't see those then you probably have the gear drive. They both operate off vacuum and the switch will be on the climate control panel. You may or may not hear any noises.

longhorn396 · 08-21-2011, 08:07 AM

ok well i appreciate the help! lol

08-19-2011, 03:14 PM	#1
longhorn396 S.D.M.F. Join Date: Jan 2007 Location: Westport, In Posts: 639	Heating/AC system question Hey guys my 94 pontiac grand am wont switch setting from vent to defrost or from vent to floor. Idk how or even where to begin looking for why the vent doors arent moveing or closing. if i can fix it easily im gonna keep the car if not im gonna sell it when i get another. Any help appriciated!!!! __________________ 1969 Chevy Longhorn 396/400 3/4 ton. 1991 Chevy Camaro RS 305/700r4 1978 Honda XL175 and XL350(the evil twin) 2006 Kawasaki ZX-14r drag bike-best e.t. 9.4@145 mph without nitrous 1971 BSA Thunderbolt 650cc

08-19-2011, 10:38 PM	#2
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,705	Re: Heating/AC system question This is a common problem and the usual cause is the blend door motor actuator. It has a plastic gear inside that strips out and won't move the door. You can replace it if you're handy but they cost between $150 and $200. You might get one for less from GM Parts direct on line. Google blend door motor for more info. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

08-20-2011, 08:00 AM	#3
longhorn396 S.D.M.F. Join Date: Jan 2007 Location: Westport, In Posts: 639	Re: Heating/AC system question What part of the dash is it in? __________________ 1969 Chevy Longhorn 396/400 3/4 ton. 1991 Chevy Camaro RS 305/700r4 1978 Honda XL175 and XL350(the evil twin) 2006 Kawasaki ZX-14r drag bike-best e.t. 9.4@145 mph without nitrous 1971 BSA Thunderbolt 650cc

08-20-2011, 12:44 PM	#4
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,705	Re: Heating/AC system question It varies by vehicle but most are in the center not far from from the heater core. I would go to the auto parts store and pic up a Haynes manual for the car. it will tell you a lot more about remove and replace and a lot of other stuff than we could ever cover here. They run about $20 and well worth it. It might be the climate control switch too, which would be easier and cheaper to fix. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

08-20-2011, 01:06 PM	#5
longhorn396 S.D.M.F. Join Date: Jan 2007 Location: Westport, In Posts: 639	Re: Heating/AC system question If its just stripped can u still hear it make noise cause i dont hear it doing anything when i do??? __________________ 1969 Chevy Longhorn 396/400 3/4 ton. 1991 Chevy Camaro RS 305/700r4 1978 Honda XL175 and XL350(the evil twin) 2006 Kawasaki ZX-14r drag bike-best e.t. 9.4@145 mph without nitrous 1971 BSA Thunderbolt 650cc

08-20-2011, 02:33 PM	#6
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,705	Re: Heating/AC system question Well let me say that I am not familiar with the mechanism that drives your door. It may be the old style vacuum can or it might be a newer gear drive . If you look under the dash and see some saucer shaped cans with vacuum lines to them then you have the old style. If you can't see those then you probably have the gear drive. They both operate off vacuum and the switch will be on the climate control panel. You may or may not hear any noises. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

08-21-2011, 08:07 AM	#7
longhorn396 S.D.M.F. Join Date: Jan 2007 Location: Westport, In Posts: 639	Re: Heating/AC system question ok well i appreciate the help! lol __________________ 1969 Chevy Longhorn 396/400 3/4 ton. 1991 Chevy Camaro RS 305/700r4 1978 Honda XL175 and XL350(the evil twin) 2006 Kawasaki ZX-14r drag bike-best e.t. 9.4@145 mph without nitrous 1971 BSA Thunderbolt 650cc



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