AM/FM radio reception

[daemoncan]

Just before winter hit last year, AM reception started getting really bad, and ultimately went away completely. Sometime mid-winter, FM reception started going, and is almost completely gone now.

Pulled radio, re-seated XM & radio antenna connections at back (grey & black wires) . No difference. Pulled antenna connection off again, and touched a piece of "telephone" wire to the center pin of the radio connector, and got some reception. Now I could just bite the bullet & buy a new antenna, but I don't want to bite off more than I can chew.

Removed cabin light to have a look at the antenna leads as they enter the vehicle. To my surprise, there are 4 coaxial wires coming from the antenna. A disconnect for two of them (red and blue) are located at the opening in the headliner where the cabin light is located. All four wires are visible behind the glove box. The grey & the black head towards the center of the console, but the blue & the red continue down behind the panel in front of the passenger door. There is another dual disconnect at this location.

Questions are:

Is there another disconnect somewhere behind the headliner for the XM & terrestrial radio? Would like to definitively rule out wiring/connector problems before flushing 100+ bucks on an antenna base.

What are the red & blue wires for? Is this some sort of active antenna, or are they for the telematics (under the passenger seat)?

Tks

 

[NORTON]

I've read that the antenna base is a powered pre-amplifier.
It can get it's power from a DC bias in one of the coaxes.
It makes sense that there are four:
XM
AM-FM
GPS
Keyfob

Possibly....

Could you find a 'pick and pull' antenna base from any Spark?

Good luck.

 

[CSW]

AM is gone in my car, and XM, but FM works fine.

I have NEVER had a car do this, totally weird.

 

[jackjack53]

The dual disconnects you’ve found at both the cabin light and the panel in front of the passenger door indicate that there could be multiple antenna modules or systems at play. If you're trying to troubleshoot or upgrade the antenna, you may want to follow these wires to identify their specific functions or consult the vehicle's wiring diagram for further clarity on the antenna system’s setup.