Heater/AC Fan Noise

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Apr 25, 2008 | 03:41 PM

darklordftt

Thread Starter

Racer

Joined: May 2006

Posts: 259

Likes: 8

From: Shortsville NY

Heater/AC Fan Noise

Hi, I have an '81 with AC. As soon as I turn the ignition key to the "run" position, I can hear the heater fan turn on... it sounds like it has a bad bearing in it (its coming from the passenger side fire wall right under the windshield). Anyways, I'm getting ready to put a new fan motor in, but it has occured to me that the fan shouldn't even be on... all of the climate controls are set to "off" and "low" speed, yet its always running (sounds like its on the "low" setting). And when I'm driving the noise will sometimes get louder. If I put the fan on "high" the noise goes away, but as soon as I return it to "low" it sounds like its spinning on a bad bearing again. Anyways, common sense tells me it shouldn't be running at all... however my fuse panel is a nightmare, and I don't doubt something might be cross-wired.

Should the fan be blowing all the time? Has anyone else had this happen? I did a search and saw how people have removed the heater core\fan cover under the hood... do I need to drain the system before removing this cover so fluid doesn't spill eveywhere?

Thanks,
Stephen

Apr 25, 2008 | 04:35 PM

Ganey

Race Director

Joined: Apr 1999

Posts: 11,520

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From: CORVETTE 77 385 C.I. TEXAS

Yes, the blower runs all the time w/ key on. I changed low to off a long time ago & have posted many times how to do it.
No need to drain the water to replace the blower.

Apr 25, 2008 | 04:42 PM

darklordftt

Thread Starter

Racer

Joined: May 2006

Posts: 259

Likes: 8

From: Shortsville NY

Quote:

Originally Posted by Ganey

Yes, the blower runs all the time w/ key on. I changed low to off a long time ago & have posted many times how to do it.
No need to drain the water to replace the blower.

wow, I can't believe its supposed to run like that all the time.
thanks for the info, I'm going to go try and search for your mod now.

Apr 25, 2008 | 04:45 PM

Ganey

Race Director

Joined: Apr 1999

Posts: 11,520

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From: CORVETTE 77 385 C.I. TEXAS

Low to Off
Disconnect connector at resistor box under hood pass. side near high blower relay & bend down the connector to dk. brown wire & reconnect.

Apr 25, 2008 | 04:52 PM

darklordftt

Thread Starter

Racer

Joined: May 2006

Posts: 259

Likes: 8

From: Shortsville NY

Quote:

Originally Posted by Ganey

Low to Off
Disconnect connector at resistor box under hood pass. side near high blower relay & bend down the connector to dk. brown wire & reconnect.

Thanks, I just went through 10 pages looking for it lol.

Apr 25, 2008 | 04:56 PM

7T1vette

Team Owner

Joined: Jan 2006

Posts: 37,637

Likes: 3,118

From: Crossville TN

The 'permanently' lubed bushings in the fan motor need to be lubed! Eventually, those things go dry. It's best just to replace it...but if it works on higher speeds, you can disonnect the low speed wire...until the blower motor gives out completely, THEN you can replace the blower motor (and rewire the LOW speed back in).