That screaming fan noise
#1
Instructor
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Join Date: Oct 2005
Location: Lake Mary, Florida
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My 78 sc has fact. a/c that has not ever been working much less run since I have owned the car. When playing with the a/c defroster sliders I slid the top one to the far right and got this screaming fan noise from under the hood. How expensive? Necessary to fix? I doubt I will ever try and get a/c up and working.. I did see what appears to be a fix it for a hundred and something..fresh air fan motor assy only from Performance Products.. hard to change out?
#2
Race Car
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If you were playing with the climate control levers, then that's the fresh air blower. It's not part of the AC. If you turned on the AC itself and the front condenser fan came on (all the way up at the front of the car, not under the dash), then it's the condenser fan. If you're not using the AC, you can disconnect the condenser fan. It's a potential fire hazard since (I'm pretty sure) it's not fused.
#3
Rennlist Member
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Before you buy a new one, go in and look at the old one first. The motor sits in a plastic housing. My housing was cracked allowing the fan to scrape against the sides. I glued the cracked housing back together then reinstalled the fan/motor assembly. It's been fine for a couple years now. As Jack, says, if the sound is coming from the front of the car, it's the condenser fan. This is the unit that I repaired. I'll try to post a photo of the unit tomorow.
#5
Rennlist Member
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Originally Posted by Porsche Newbie
Jack, yeah pretty sure it was that fresh air blower motor.. never changed one out so.. I figger I might need to do this..
Good luck on the fix.
#6
Burning Brakes
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My fresh air fan on my 83 does not squeal, but does have a bit of a intermittent squeak, mostly noticeable at higher fan speeds. I have been wondering if the bearings were such that they could be lubricated at all. Just have not been able to look closer yet.
#7
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Originally Posted by Porsche Newbie
Jack, yeah pretty sure it was that fresh air blower motor.. never changed one out so.. I figger I might need to do this..
It's really easy to change out. Remove the trunk carpet. Remove the 4 bolts that hold the cardboard panel that covers the ventilation junk. Then remove the one cable that moves the baffles inside the fan housing. Be careful not to drop the spring clip that holds the cable to the housing. I lost mine...had to order a new clip from the dealer...
Remove the hoses from each end of the blower housing. Then, I believe there are only a couple bolts that hold the housing on the car.
Get the entire housing on your work bench. Remove the wiring from the blower motor. Take note of how the two baffles are placed in the housing. You'll need to get them back in there in the same orientation. There are 6 circle clips that hold the housing together. 2 on one side, 4 on the other. Get these clips off and the entire housing will 'break in two' so to speak. The blower motor will come away, as will the two connected baffle assemblies.
There is a gasket that helps hold the squirrel cage/blower motor in the housing. Be very careful of that gasket, since you need it again and it does not come with the new blower motor part. Remove it from the old blower motor assembly. I cleaned my housing up a bit before reassembly to get 22 years of dirt out of it. I also lubed the 4 pivot points for the two baffles that are encased in the blower housing.
Install the old gasket (I treated mine with Vinylex since it was so old) on the new blower motor. Then, you just reassemble the whole thing. Getting the circle clips back on without scratching up the plastic housing too much was the only thing that was of any trouble for me, and that's pretty darn minor. So, it's a pretty easy project for most people and won't take much more than an hour if you're handy. I could probably do it again in 20-30 minutes.
With the A/C blower and the fresh air blower now working in my car, it's like a small hurricane blowing inside the car!
Hope this helps,
Jay
90 964, 84 3.2
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#9
Rennlist Member
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Yeah, I replaced my fresh air blower pretty easily. I ordered just the motor, not the motor with the fan blade, so I spent quite a bit of time prying that fan blade off the old, rusted motor. Otherwise, it was a 30 minute job.
#10
Team Owner
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Yeah, I replaced my fresh air blower pretty easily. I ordered just the motor, not the motor with the fan blade, so I spent quite a bit of time prying that fan blade off the old, rusted motor. Otherwise, it was a 30 minute job.
even worse than me ..
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