Heater fan sounds like an egg beater

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Animal Lawyer

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When I tried to use heat yesterday the fan first started a high pitched warble (which went away when I took it off high speed) then it started sounding like an egg beater (for those younger members, similar to a baseball card in the spokes of a bicycle). I am assuming a bad bearing? and the shaft angling down such that the cage attached to the shaft is hitting the wall? 

How hard is it to remove the heater fan ('73 vert w/air)? Can it be done without disassembling the dash? Where would I find the instructions to remove it? Replace the fan motor with new (repro) or find a good used oem?

In the words of Emily Latella, "It's always sumphin!"

 

BUCKWHEAT

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take out driver's seat to give yourself some room. blower and squirrel cage come out as a unit. about five small machine screws, and take off wire plug-ins on top of the housing. be patient. its awkward but not impossible. wide selection of new units from Rock auto to ford as suppliers.
 
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Can't help on taking it out on a 73 but I would check the squirrel cage to see if it came loose on the shaft or on its hub. That would also make the sounds you are describing.
 
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The squirrel cage also has small counterbalance weights on them for balance just like balancing a tire. I had one come off which cause the cage to sound like an egg beater especially at higher speeds. 1-4-2022 3-30-26 PM.png the
 

machattack

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My 71 was making a bunch of noise. Turned out it was debri that got in from the cowl. Cleaned it out and no more noise. Lucky
 

Bobby

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The blower motor should be able to be removed without taking the blower unit out. It’s a pain but can be done. It’s just over the gas pedal. Best thing to do it buy a new motor and squirrel cage. Classic auto air has them or eBay. Test the motor before installing to verify polarity (rotation) because they do things different in Chycom land. On my application, the red ended up being the ground and the black being 12v hot. If the leads are reversed, it’ll run backwards and the will be very little air flow.
 
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The blower motor should be able to be removed without taking the blower unit out. It’s a pain but can be done. It’s just over the gas pedal. Best thing to do it buy a new motor and squirrel cage. Classic auto air has them or eBay. Test the motor before installing to verify polarity (rotation) because they do things different in Chycom land. On my application, the red ended up being the ground and the black being 12v hot. If the leads are reversed, it’ll run backwards and the will be very little air flow.
Agree. I have removed the blower motor with the A/C box in place. Remove the front seat to give you more room. Otherwise is a matter contortionism and alignment. I would remove it fist to see what's going on. Maybe it is an easy fix. You can bench test it to see if you can replicate the sound. At that point you can decide what you need, cage, motor, housing, etc.
 

DSwan

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I have to replace the blower motor on my 73 mach with no A/C. I can see the squirrel cage on the passenger side after removing the duct work, but I can't see how the blower comes out. Any ideas?
 

swice

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When I tried to use heat yesterday the fan first started a high pitched warble (which went away when I took it off high speed) then it started sounding like an egg beater (for those younger members, similar to a baseball card in the spokes of a bicycle). I am assuming a bad bearing? and the shaft angling down such that the cage attached to the shaft is hitting the wall?

How hard is it to remove the heater fan ('73 vert w/air)? Can it be done without disassembling the dash? Where would I find the instructions to remove it? Replace the fan motor with new (repro) or find a good used oem?

In the words of Emily Latella, "It's always sumphin!"
I experimented with many things to avoid replacing the fan unit, I found that by adding about 1/4 cup of F type transmission oil to the fan motor by way of the opening on the top of the fan motor housing, the noise vanished and has never returned. I used a small tube and simple pump to reach above the gas pedal to the fan motor, work the tube into the fan motor ventilation opening in the housing, then infuse the F type transmission oil into the fan motor. The smell went away in a few days, this was a year ago and I use the car almost everyday. The fan is so quiet that I can't believe it's on. I had purchased a used complete replacement fan/cage and never had to use it.
 
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I have to replace the blower motor on my 73 mach with no A/C. I can see the squirrel cage on the passenger side after removing the duct work, but I can't see how the blower comes out. Any ideas?
I don't now if the A/C version is different but there are three (or maybe 4, can't remeber) screws facing the passenger side that have to be remove plus the wiring.

Air Capture.JPG
 

DSwan

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I don't now if the A/C version is different but there are three (or maybe 4, can't remeber) screws facing the passenger side that have to be remove plus the wiring.

View attachment 58833
Mine is quite different, it's on the passenger side and I can't see anyway to remove it. It's right there where I can see it but it almost seems like the whole system will have to come out. I've already cursed the engineers, I'm hoping it's just me missing something.
 

Hemikiller

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Mine is quite different, it's on the passenger side and I can't see anyway to remove it. It's right there where I can see it but it almost seems like the whole system will have to come out. I've already cursed the engineers, I'm hoping it's just me missing something.

Heater box has to come out, the fan is mounted on the firewall side. The complete step by step process is detailed in the factory shop manual. Forel has them as instant e-book downloads now.


If you don't mind waiting a couple days for shipping, the Detroit Iron CD includes a complete 73 wiring diagram set as well.

 

DSwan

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Thank you for the info. I was afraid it wouldn't be as easy as it could've been. It's frustrating being able to see the whole fan but not be able to remove it without going through all of that. Thanks again for the link and the info.
 
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Working on anything under the dash in these cars is annoying to say the least. From the vacuum systems to the heater/blower - everything is upside down and a PITA. Just pull the seats, and throw some foam down, and get a hunk of leather to bite-down on.
 

midlife

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Working on anything under the dash in these cars is annoying to say the least. From the vacuum systems to the heater/blower - everything is upside down and a PITA. Just pull the seats, and throw some foam down, and get a hunk of leather to bite-down on.
I use trained ferrets for jobs like this.
 
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