Loud hum/noise when using vent fan

[John Tiernan]

Hey y'all

Haven't been able to find anything out about this online so maybe someone here has experience or insight.

2 things happening in my '03 DeVille:

1) When using the vent, I can hear a loud hum/strained noise coming from the dashboard which increases in volume as the fan does.  Always correlates.  Fan is off, no sound.  Fan up high, hum gets louder & higher pitched.  So it sounds like the vent could possibly be blocked by something, although air flow seems fine.

2) A/C is not working.  Feels exactly the same as just having the vent on so need to be ready for the summer.

 

I'm hoping the sound could be what's causing the AC to not work and it's not something serious.  Not really the best with auto repairs but if it's simple I'm hoping I can do it myself.

Anyone have some insight?

 

Thanks in advance

[RubberCarrot]

My experience with this sort of thing has not been on a Caddy but the fix to the fan noise problem might just be something simple like debris in the fan cage.  Look into replacing the blower motor.  In many cases it is not that tough.  I did it on my truck (it made a terrible noise and output was next to nothing) and when I pulled the blower motor out (3 screws) it was 75% filled with insulation from within the duct work.  Why?  How?  Don't know, don't care.  I cleaned it out and put back and life was good.  Took the replacement back to the parts store.

Is that your AC problem?  I doubt it.  But at least it may help with the blower noise.

[rockfangd]

Sounds like it may be a bad bearing in the blower motor.

When were the cabin filters last replaced?