I don't even know where to start troubleshooting this. I know that in the past (before I got it) there was probably some water damage based on a stain and saggy headliner. At some point soon I will drop it to repair because it bugs me when it flaps in the wind when the windows are open. Is it possible that water has messed up a connection? Is there a good way for me to check that power is getting to the antenna without dropping the headliner?

What about that module, where is it located and can I test the signal and power there?