Car Audio Install Garage

I'm on WEEK TWO trying to find an answer to this. '95 Town Car with factory Lux Sound System. Not the JBL. Stock system consists of a control unit in the dash, that resembles a standard radio. Actual tuner and amp is trunk mounted. There are TWO antenna leads going into the trunk unit. It's my understanding there's an AM antenna built into the rear window glass, and TWO FM antenna grids. One of which is in the rear glass, and one in the windshield glass. The FM antenna system is called a "diversity antenna". The two FM antenna coax's are junctioned into a box, then sent to the trunk amp/tuner unit.
So far, I'm GUESSING one of the coax's that goes into the amp unit is FROM the FM coax junction box, and the OTHER coax into the amp is from the AM antenna.
There is NO coax leading up to the dash head unit.
THE QUESTION......Where do I loop in an FM Modulator, for the CD Changer I'm installing????

Somebody will have to be TOTALLY familiar with this type of Diversity Antenna System" to answer this for me.
I have a service CD for the car, and it has a wiring diagram of this system on it. But, it really doesn't SPECIFICALLY state exactly what the 2 coax's going into the trunk unit are.

Sorry can’t remember ever adding a CD changer to a 1995 Town Car factory Lux Sound System. I do however have an easy fix for you. Unplug each coax one at a time, which ever one cuts out the FM reception use it.

Wow. That's funny !! Just today, I decided I would try that. Then I checked in here, and boom, you had the same SIMPLE idea I never even thought of. I guess that's what happens when frustration sets in. It did the trick. It was the bottom coax.
Thanks for the help dude. I was so confused, I guess I just lost all simple logic.

No problem, happens to the best of us. Always helps the have a second head on a problem, that is what the Install Garage is all about.