I did the retrofit on my 2004 with Assist and changed it to the Bluetooth only module. I finally got a hold of a snap-in adapter for my phone (K750).

Question is:
The snap-in charges just fine but I don't think the car's external antenna is working. The reception bars keep fading. How can I check? Is the handset supposed to have full reception the second it's plugged in? I remember being able to check the reception with my Assist but I can't anymore with my bluetooth only module.

Thanks in advance.