AC Blower not moving much air ? - Chevelle Tech
Heating & Cooling Heating, cooling and air conditioning

 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 12 (permalink) Old Nov 12th, 08, 9:02 PM Thread Starter
Tech Team
 
Join Date: Apr 2003
Location: Florida
Posts: 59
AC Blower not moving much air ?

Hello and thanks for any help... I have a 1970 Chevelle with factory AC . I replaced the blower motor but other than HI it just doesnt seem to move much air.
Has anyone used a late model Fan Blower motor that moves alot of air ? If so , what was the blower unit from ?
Or any other mod's to make the system work better ?
ihav1 is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old Nov 13th, 08, 9:22 AM
Senior Tech Team
 
Join Date: Jan 2004
Location: Ca
Posts: 1,193
Re: AC Blower not moving much air ?

I replace the motor on a Chevy PU years ago, and got it from the junk yard, and was not from the same type vehicle. So I put the motor in with the fan. It ran good but little air came out. Took it back out, and checked it with the old one.The fan blades were in opposite direction, just changed the fan,and worked like it should.Maybe that's your problem?
442 Harv is online now  
post #3 of 12 (permalink) Old Nov 13th, 08, 3:53 PM
Senior Tech Team
Tom
 
Join Date: Mar 2006
Location: Northern Ohio
Posts: 1,008
Re: AC Blower not moving much air ?

Quote:
Originally Posted by ihav1 View Post
Hello and thanks for any help... I have a 1970 Chevelle with factory AC . I replaced the blower motor but other than HI it just doesnt seem to move much air.
Has anyone used a late model Fan Blower motor that moves alot of air ? If so , what was the blower unit from ?
Or any other mod's to make the system work better ?
Although those systems were kind of wimpy when new, the problem isn't likely the fan motor. The most likely cause is the outside of the evaporator caked with 38 years of dust, dirt, and debris from the unfiltered air. Pull the blower motor and have a look.
lsrx101 is offline  
post #4 of 12 (permalink) Old Nov 13th, 08, 4:38 PM Thread Starter
Tech Team
 
Join Date: Apr 2003
Location: Florida
Posts: 59
Re: AC Blower not moving much air ?

I have had the entire unit out and restored. New Evap., POA , restored box , wiring , Fan motor , relays , etc...
Seems to work - Ok on HI , but the other speeds move little air.
Has anyone done anything to update the motor or squirrel cage for more Air ?
Someone told me to take one from a late model car , like a Monte Carlo, but the blower motor is shaped different. Just looking for some good idea's from someone who has already been down this road....
ihav1 is offline  
post #5 of 12 (permalink) Old Nov 13th, 08, 5:22 PM
Lifetime Premium Member
leo
 
Join Date: Oct 2003
Location: Colonial Beach, Va
Posts: 9,763
Re: AC Blower not moving much air ?

Make sure the blower motor is spinning the correct way, also, the A/C blower motor is different than the non A/C motor, make sure that is correct also.

Leo Paugh
Maryland Chevelle Club #017
A.C.E.S.#3731
progress has little to do with speed, but lots to do with direction
www.mdchevelleclub.com
LeoP is offline  
post #6 of 12 (permalink) Old Nov 13th, 08, 6:08 PM Thread Starter
Tech Team
 
Join Date: Apr 2003
Location: Florida
Posts: 59
Re: AC Blower not moving much air ?

I am pretty sure its the AC Blower as it has a ground and power terminals. Like i said, it works ok on HI , just the other three speeds dont move enough air or very little.
Is there a better cage , faster blower motor , better relay ?
Does anyone know what other blower might fit the case ?
ihav1 is offline  
post #7 of 12 (permalink) Old Nov 13th, 08, 11:07 PM
Lifetime Premium Member
Tom
 
Join Date: Nov 2000
Location: Franklinville, NJ
Posts: 15,274
Garage
Send a message via AIM to BlueSS454
Re: AC Blower not moving much air ?

IF it's workig on high, and barely on any of the other speed selects, it's a current problem. Check the blower motor resistor that is screwed into the heater box on the engine side. It's the one with the 3 spring looking coils.

Tom Rightler, MCC VP & Newsletter Editor
1970 SS Best ET: 12.31@108 MPH
1969 Malibu
1969 Dodge Charger
1970 Chevelle Convertible
Maryland Chevelle Club
BlueSS454 is offline  
post #8 of 12 (permalink) Old Nov 14th, 08, 10:11 AM
Senior Tech Team
Mitch
 
Join Date: Nov 2003
Location: Stillwater MN
Posts: 1,161
Re: AC Blower not moving much air ?

Many of the doors to direct the air are vacuum operated. The engine needs to be running for the controls to work properly and get the air into the cab. If you have tried it with the engine running, are the controls working ??

70 Chevelle SS 396, M20 Canadian Z25 project.
66 Chevelle SS 396, Atlanta built 138 driver/project.
66 Chevelle Malibu Fremont built Marina Blue on Blue
67 Camaro, ss/rs 350 LA built driver/project.
62 Impala SS
38 Chev coupe...355, 200r4, 8.5" 3.08 posi
52 Chev 2 ton flat bed
Second_chance_SS is offline  
post #9 of 12 (permalink) Old Nov 14th, 08, 10:33 AM
Lifetime Premium Member
Jonathan
 
Join Date: Dec 2007
Location: Siler City, NC
Posts: 3,657
Re: AC Blower not moving much air ?

Cheap after market blower motors are not wound as tight as OEM units. I was able to reuse my 69's original unit and it blows musch stronger than my 72's with an aftermarket motor.

https://www.coolharts.com
http://www.carolinachevelle.com/

72 Chevelle Malibu
72 Chevelle Malibu In Process

NCOA #6446
ACES #8153
Carolina Chevelle Association #147
Maryland Chevelle Club #834
Chevelle_Nut is offline  
post #10 of 12 (permalink) Old Nov 14th, 08, 10:39 AM
Tech Team
Steve
 
Join Date: Sep 2007
Location: Broward County Florida
Posts: 563
Re: AC Blower not moving much air ?

Quote:
Originally Posted by BlueSS454 View Post
IF it's workig on high, and barely on any of the other speed selects, it's a current problem. Check the blower motor resistor that is screwed into the heater box on the engine side. It's the one with the 3 spring looking coils.
I have the same issue. However, I first had a problem with no high on the fan. I was then advised (on here) that there is seperate fuses for the other speeds, and one high speed fuse that I located under the hood. Is it possible that that High speed fuse is good and the other bad?

Steve CCPD166 Broward County Florida
1970 Chevelle SS
396/350
ccpd166 is offline  
post #11 of 12 (permalink) Old Jun 30th, 09, 3:39 AM
Tech Team
James
 
Join Date: Dec 2006
Location: Orange County, CA
Posts: 288
Re: AC Blower not moving much air ?

Same kind of question here. I've taken everything out and cleaned up the whole A/C system, new blower motor, etc. I know the car has a 40 year old design, but is there a more powerful blower motor that might make it match today's late model standards. My friends new Civic A/C feels so nice, are new cars systems just better at sealing in cool air?
69307/350Chevelle is offline  
post #12 of 12 (permalink) Old Jun 30th, 09, 5:13 AM
Senior Tech Team
Tom
 
Join Date: Mar 2006
Location: Northern Ohio
Posts: 1,008
Re: AC Blower not moving much air ?

Quote:
Originally Posted by 69307/350Chevelle View Post
Same kind of question here. I've taken everything out and cleaned up the whole A/C system, new blower motor, etc. I know the car has a 40 year old design, but is there a more powerful blower motor that might make it match today's late model standards. My friends new Civic A/C feels so nice, are new cars systems just better at sealing in cool air?
Newer cars are just better designed for better airflow and volume.
Back in circa 1970, most GM cars were known to be rather wimpy as far as airflow out of the ducts, except on High Blower (Thus the High Blower Relay to put as much power as possible to the motor). Then they were only "kinda" wimpy. Chrysler products were even worse at that time. Ford was the only one back then that could boast that the output from the dash vents could "blow your hair back". Even they weren't up to todays expectations.
The High line GM cars (big Buicks, Olds, Etc) were better than the Low or Intermediate Line cars for airflow, but even they were not what you would expect today from even a "cheap" car.

Cars of the 40's and 50's had very poorly designed airflow (heater) systems that were just barely better than nothing. The systems of the 60's and 70s were comparatively far superior performers as the years progressed, but surely not even good compared to today. Fast forward to the 80's and they were better yet, but still not up to todays standards. Only in the late 80s and into the 90s did GM produce MVAC systems that compare to today's systems. That same progression held true with the other manufacturers, but GM historically has always had the "wimpyist" airflow systems as compared to the "other guys". Actually, that still seems to hold true even today IMHO. The difference just isn't as noticeable.

There might be ways to improve the airflow of those older cars, but I've never delved into it.

Today, the best you can do is meticulously seal leaks in the ductwork, make sure everything is nice and clean, and make sure the blower motor and it's wiring is up to par on these older cars. They were great performers compared to their predecessors, but you will never get 2009 performance out of them.

"I didn't defend myself. I killed the crap out of him!" Norma Bates
lsrx101 is offline  
Sponsored Links
Advertisement
 
Reply
Gear in this thread - Powered by O'Reilly Auto Parts

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome