I need some help to fix my factory Sirus system.
Here's the issue narowed down.
When the power to the unit in the trunk is pluged in, I loose most of my FM reception.
When I unplug the power to the trunk Sirus unit, I regain FM reception, but ofcoarse I loose all Sirus functions.

I first checked the connections to the FM amp in the c pillar, all were conected.
I do have 12v to the power plug into the trunk Sirus unit.
I have confirmed my Sirus account is current.
I do have a good Sirus signal.

I would be happy with just Sirus (no FM) for the trip comming uo, but cannot tune the sirus unit, as I cant get FM and Sirus at the same time.

I would like to keep the factory Sirus unit and use it on trips, but right now a no-go.

I've looked at all the diagrams (both Sirus and Jag) and am at a standstill.
I've checked any fuses that should be affected.
1 rear screen heater
2 trunk acc
Here's the questions I dont want to ask
Could it be the following:
1) FM amp (c pillar)
2) FM switching box (buried deep behind the head unit) Please dont it let be.
3) Sirus module in the trunk.

This acts like the time I had the FM transmiter in the "ON" mode thru the Sirus controler. You will get a lot of FM interference.

This all started when the body shop disconnected the Din "to controler", and the "to FM" plug. I doesnt seem that unpluging and pluging back in should have any affect, And probably just a coincidence, unless they shorted out on the body and blew a fuse that I havent found.

I know most people just remove the Factory Sirus (poor quallity), but I would like it until I can get my hands on the new great streaming unit from Venelin. Are these Sirus componants that unreliable?
I know I'm missing something simple!!!

Any help would be great, my trip is comming up in July with a full car.
Mark