sensor above head in headliner

Doonatic · May 8, 2017

hello everyone. Can someone please tell me what the sensor above the drivers head is, and what its function is? It is mounted in the headliner. I have an 03 2500HD LTZ 4x4 Crew 6L with (what was) Bose. I have heard the thing vibrate and can get pretty loud at times. mostly during the colder months.

dewfpo · May 8, 2017

Microphone for Onstar.

DEWFPO

jusbecuz · May 8, 2017

I have an 04 and had the same buzzing sound. It's actually a fan for the automatic temperature control. Pretty easy to replace. There are some videos on you tube I used for reference.

ACDelco 22834330 Aspirator

txab · May 8, 2017

It's called an aspirator. Part of the MVAC system

casey.mikl · May 8, 2017

Microphone for Onstar.

DEWFPO

Nope. As stated below. It's a fan and is a temp sensor.

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txab · May 9, 2017

http://www.truckmodcentral.com/forums/f63/how-replace-auto-climate-control-aspirator-gmt800-chevrolet-tahoe-1468/

casey.mikl · May 9, 2017

Probably has some dust. Maybe get a can of compressed air and try to blow it out. Think there $50 to replace.

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dewfpo · May 9, 2017

Nope. As stated below. It's a fan and is a temp sensor.

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Thanks, I stand corrected. My '05 with automatic HVAC doesn't make any noise and the only 'sensor' like fixture I see is the microphone.

DEWFPO

jusbecuz · May 9, 2017

I tried cleaning mine with air and lubrucating it but neither worked. I got mine from Walmart online for around $20 and picked it up at the store.

jusbecuz · May 9, 2017

Thanks, I stand corrected. My '05 with automatic HVAC doesn't make any noise and the only 'sensor' like fixture I see is the microphone.

DEWFPO[/quote

That's what I thought as well, until I researched it and took off the cover.

Doonatic · May 9, 2017

thanks everyone. I looked all over my Haynes manual, and the owners manual and there was nothing on it.

also is there an in cabin air filter someplace? ive never seen it before.

davester · May 9, 2017

There MAY be one. Google "gmc sierra 2003 cabin air filter"

It's not clear to me when GM put them in (they were doing it, then they stopped, and I think they've started again).

If your truck doesn't have one (my '04 doesn't), you can retrofit it into the truck, by cutting open the slot for it, and either buying or making the cover to hold the filter in.

Dmaxing · May 9, 2017

thanks everyone. I looked all over my Haynes manual, and the owners manual and there was nothing on it.

also is there an in cabin air filter someplace? ive never seen it before.

Non in mine 2007.5

dewfpo · May 9, 2017

There's no cabin filter in my '05 either.

DEWFPO

C/K Man · May 10, 2017

GM trucks had a cabin air filter up to 2002. Some 2003's were built with leftover 2002 HVAC boxes, and while those usually do not have a filter, you can put one in. Most 2003's had the redesigned HVAC box with no filter. 2007 and up do not have a cabin air filter, but there is a kit available through AC/Delco to add one. 2015 HD's and newer have cabin air filters.