Dash - Sound Problem

I have had my dash torn apart all the way down to
just the molded black frame that everything slides in or attaches too.

i can not find this click/raddle sound, almost like a washer hitting plastic sound.

just to the right of the climate controls, and just

behind and to the left some, of the black box thing behind glove box is where the raddle is.
I have took radio out, climate controls out etc. raddle still there, comes more from behind the glove box to the left side.
The sound is behind the black framing and glove box, which is enclosed.
there is no way i can see how to get into it without tearing up the dash,
my FSM don't show me whats in or behind the black box thing.
Does anyone know what that black box is? or what could be back there to raddle. to the left of it?. Or have PICS?

One Hint! is if i have the heater turned on, it does not raddle at all? seems like if heat is running throught the vents it stops?
But not when a/c is on sound still raddles? so i ruled out blower fan? sort of.
Any Ideals? this noise is pretty loud .
.

Turn the radio up louder.

That black box behind your glove box is the housing that holds your evaporator and heater control. It is a self contained heater/ac box. If you were to take the entire dash out that is the last thing to come out. It could be the door that is molded into it that diffrentiates between fresh and recirculated air.
THere is nothing but firewall behind it. It's mounted to the firewall.

What year jeep?

my jeep is a 2001 sport,
dealer said it is a major thing to do,
that there is not any simple way to get to it without taking dash off and tearing up ac/ etc.

i guess i'll live with it.
too much trouble.
but it doesn't make the noise if the ac or heat is running?
but does make the noise if just regular air from outside coming in vents

Probably a blend door, or maybe linkage isn't connected......just a possibility. And yeah, it's a pretty major job because there's so much to remove to access......

Heater core's werent put in the most user-friendly spaces....and that's what's in the black box!

if I tore my jeep apart everytime I heard an odd noise, I wouldn't have anything left.

My drivers side rear door would always squeak. Took it apart and found nothing! So I lived with it for about another year....always have the radio on so it wasn't a big deal....but....

Apparently the door gasket just needed some lubrication. I actually found that out on accident. I was cleaning the door jambs and used some dashboard cleaner/shiner on the gaskets to make them more black and that cured the problem! No more squeak, easy fix.

Just an FYI for a squeak coming from a door.....it may not be something inside!

I know this if real old, but did anyone find anything more about this?