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According to a Technical Service Bulletin released by General Motors, cabin air filters(which is what you're looking for behind the glove box) were discontinued during the 2003 model year. This means your vehicle is not supposed to have one installed. Regardless, this filter would have no affect on the operation of your a/c system.
Can you clarify exactly what your A/C system is or is not doing? Is it blowing cool air from the vents?
Thanks.
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Sunday, September 15th, 2019 AT 9:43 AM