Heater Fan
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Pro
Joined: Sep 2000
Posts: 552
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From: Oneida WI
Heater Fan
1971, A/C
My heater/air conditioning fan quit working. The fuse is ok. Relay is new. I checked the heater fan switch with a test light at the relay and that is working. Is there a way I can connect power directly to the heater blower to tell if it is working? Any trouble shooting tips would be apprieciated.
My heater/air conditioning fan quit working. The fuse is ok. Relay is new. I checked the heater fan switch with a test light at the relay and that is working. Is there a way I can connect power directly to the heater blower to tell if it is working? Any trouble shooting tips would be apprieciated.
Safety Car
Joined: Jun 2002
Posts: 4,135
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i had to remove the coolant recovery tank, then it came out along side the air condt--here' a photo showing the spacer i made for running the bigger blower motor/squirrell cage...notice the black sticky a/c rope i used to stop a small air leakwhere the tin spacer mated up to the old fiberglass firewall where the fan used to bolt up to-------
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Safety Car
Joined: Jun 2002
Posts: 4,135
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all the blower moder does in either blow air across the heater core(like a small radiator) or across the a/c coil (to blow cold air)its just a motor w/ a squirrell cage attached to it,,its just sitting there in a pleumn waiting to do 1 or the other- it just blows air-you change air direction by way of the dervirted door
Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
Originally Posted by carl a
all the blower moder does in either blow air across the heater core(like a small radiator) or across the a/c coil (to blow cold air)its just a motor w/ a squirrell cage attached to it,,its just sitting there in a pleumn waiting to do 1 or the other- it just blows air-you change air direction by way of the dervirted door
IN FACT the above is rong.....the air is ALLWAYS blown through the a/c evap coil, wether it's cooling or not....THEN goes to a diverter setup to get heater/non heated.....then to the ductwork....
GENE
Safety Car
Joined: Jun 2002
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Yes you are correct, the a/c coil is mounted right next to the blower ,point i was trying to make is IT HAS NOTHING TO DO WITH THE REFRIG IN THE SYSTEM. iwas trying to explain the basic works of the system, since it seems like he didnt understand, i didnt want to overcomplicate it,thank you for correcting me
Safety Car
Joined: Jun 2002
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unplug the wiring,,and take the hex bolts off that are holding it on,,you probably have to remove the coolant recovery tank first,,then it comes out,,you can up grade it to a bigger blower motor but the squirrell cage is 1-1/2 '' wider(deeper) so youll have to build a shim,,its in the photo i posted for you,,,i went to menards and bought a ''stove cap'' for capping a stove pipe io believe it was 7'' wide by 2''-------- i cut out the center for the squirrell cage and bought the same diameter bolts,,only 2'' long ,,,i used a vaccume line for a gasket by slicing it lengthwise,,you can see that also if you look in the photo,,,it improved the airflow somewhat,,,,,,,,,,,,,,,,,,,,,,,,,,carl
Burning Brakes
Joined: Oct 2001
Posts: 842
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From: Woodruff SC
St. Jude Donor '10
I had that problem also. The wire going to the top of the fan was worn out or something. Replaced the connector and it has worked fine since. I could turn the fan and switch on and wiggle the connector and it would come on. Try that first.
Race Director
Joined: Oct 2000
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From: Kansas City, MO ...I'd like to go fishing and catch a fishstick. That'd be convenient. - Mitch Hedberg
Not sure of your '71, but I changed the blower motor on my '80 last week. It is accessible from the engine compartment. It is on the passenger side, under the top edge of the fender mounted to the airbox. It is held in by 4-6 screws, can't remember exactly. There is a power wire and a ground wire. The terminal for the ground wire is a bent tab held in place by a mounting screw. Be patient and work the blower motor out of the rat's nest of crap in front of it. Once out you can easily change the squirrel cage to the new one if needed.
My blower motor was $15 at the local parts store. Don't forget to get a sealant or weatherstripping for reinstallation. What's on there now is not reusable.
My blower motor was $15 at the local parts store. Don't forget to get a sealant or weatherstripping for reinstallation. What's on there now is not reusable.
Safety Car
Joined: Jun 2002
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Originally Posted by Tom Johnson
Is the blower motor under the air conditioning box on the firewall?
Racer
Joined: Apr 2005
Posts: 339
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From: San Diego CA
It sounds like you're determined to take out that blower motor! If you haven't already, there's one more sanity check you can make.
The blower receives power from two different sources, at different times. For all blower speeds EXCEPT HIGH, power is routed through resistors that limit the amount of current to the blower.
When you turn your blower on to the high position, the resistors and a/c relay are by-passed, and power is connected directly to the battery (via the relay bus on the left inside fenderwell).
If all speeds don't work, it's a pretty good bet that your blower motor is bad.
BTW - If it was me, before I did all that work of removing the blower, I would do what fast idle recommended and run a hot wire directly to the blower's positive terminal. Make sure the other terminal is grounded.
Good luck...
The blower receives power from two different sources, at different times. For all blower speeds EXCEPT HIGH, power is routed through resistors that limit the amount of current to the blower.
When you turn your blower on to the high position, the resistors and a/c relay are by-passed, and power is connected directly to the battery (via the relay bus on the left inside fenderwell).
If all speeds don't work, it's a pretty good bet that your blower motor is bad.
BTW - If it was me, before I did all that work of removing the blower, I would do what fast idle recommended and run a hot wire directly to the blower's positive terminal. Make sure the other terminal is grounded.
Good luck...
Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
IF you have done any starter motor work recently, you may have that heavy black 10 ga wire with the 3/8 loop on it connected to the battery positive on the starter, that is the ground for the blower motor, and wiper motor.....I replaced mine some years ago, to top of the intake manifold, then again, all my wiring is custom.....
GENE
GENE