[bobnorris1]

My 99 blazer has a AUX button on the face,, where is the jack?

 

[chevymec]

I think that may be for a cd changer.

 

[bobnorris1]

It dosent have a CD

 

[chevymec]

Most didn't but I believe most radios had that button regardless.

 

[bk2life]

My 99 blazer has a AUX button on the face,, where is the jack?

No input..its for CD

 

[aitch]

I'm not sure, but I thought I saw somewhere that it may be on the back of the head unit's chassis.

 

[oldeerslayer]

There's a connector on the back of the radio to plug in the CD which mounted in the console when a cassette radio was installed. It was an option. So your Blazer might not have it.
They also came with CD radios and a aux cassette that hooked up the same way.
Todays cars have neither. You just connect your iphones music library via Bluetooth.

 

[Harley]

The connector on the back can be used to hook up your own Auxiliary input if desired, but have to know what you're doing as far as communicating with the radio. A buddy of mine made me a Bluetooth adapter for the 1.5 DIN radio that worked well enough while I had it. I switched to a Double DIN down the road, so using a 3.5mm to tape adapter for my phone now. 😅