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AC/Htr Fan Noise

2K views 6 replies 3 participants last post by  Matera97 
#1 ·
My wifes 2001 Catera Sport began to make a loud thumping noise. I found a cabin filter under the hood on the right side of the firewall. (did not even know it had one) It had sucked in so I removed it thinking that was what was causing the noise. When I turned on the AC blower the sound continued. I inspected the inlet side of the housing and found nothing hitting the fan blade. (Not easy to do) Is it possiable that the filter was keeping the fan quieter? Sounds stupid but the motor seems to be just fine, it blows better than before, cools better.....
 
#2 ·
My wifes 2001 Catera Sport began to make a loud thumping noise. I found a cabin filter under the hood on the right side of the firewall. (did not even know it had one) It had sucked in so I removed it thinking that was what was causing the noise. When I turned on the AC blower the sound continued. I inspected the inlet side of the housing and found nothing hitting the fan blade. (Not easy to do) Is it possible that the filter was keeping the fan quieter? Sounds stupid but the motor seems to be just fine, it blows better than before, cools better.....
Unless something else was sucked in and has gone past the blower into air mixers/diverters/dampers, it is most likely one of those pieces flapping. Try turn the controls differently on driver passenger side. Say Driver Hot and passenger cold and see if it changes the sound. There is a sequence to reset the actuators but I don't seem to find it right now. It is related to get the actuators to re-home even though these are supposed to do that automatically.

Is the sound plastic hitting metal or plastic to plastic rattle or metal to metal? Almost everything past the blower is plastic if it helps in troubleshooting and the last point of plastic/metal strong source of noise has to be the blower motor or if one of the fins on blower is broken or something dependent upon how the sucked in filter affected the motor.

Good luck and I will update this post or add new if I find something else.

Welcome to Cadillacforums too.
 
#3 ·
I thought the actuator reset was pressing and holding drivers knob, and the AC ON/OFF switch, I remember R-Caddy posting that, when I was getting hot on one side and cold on the other. Now I'm getting no air at all. It sounds like it wants to come on make that little noise, when car is turned on or off, but no blowing air. Any ideas?
 
#4 ·
A blocked cabin filter if properly fitted can make it very bad close to no air which I noticed and as soon as the mechanic removed the cabin filter, it was good. Then I put in a new cabin filter and it is good.

I believe your comment on resetting is correct I just forgot which two simultaneous buttons to press.

Does your Fan move and under manual control does it make sounds which are different as you manually increase and decrease fan speed? If this test is positive then at least your hedgehog resistor may be OK (very expensive new).

Also may want to reach down from the passenger side under the glovebox and feel if there is any air with fan on and I believe you can move the baffle/deflector (I never did but my mechanic did so caution in case it damages any actuators, etc.).

Cheers.
 
#6 ·
The way you describe it appears like a failed blower motor or motor bearings ready to blow a fuse unless these have thermal protection. You may want to if you have access to it try to nudge it along with a soft piece of plastic or something if it starts going. Lately I have not taken a look in that area if that is going to be possible once you remove the filter.

Good luck.
 
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