Speaker kicks in and out; not speaker; possibly wiring?

I have a 1999 Mitsubishi Galant LS. When I bought the car used two years ago, I noticed that when the driver door was opened half way the door speaker would cut out, but once the door was shut it would come back on. I rigged it to work by just moving this plastic tube of wires that went from the door to the body of the car. I only had to do that once and it worked for at least a year. Just yesterday it kicked back out again. I moved the tube like I did before and it didn’t come back on. For some reason, that tube of wires needs pressure for that speaker to work. But why is it not working now? I know it is not the speaker itself because it would kick in and out when I would move the tube around. Do I have to completely re-wire that speaker from radio to speaker? Or can this just be an easy, cheap fix? If I have to re-wire it, how do I do this?

Thank you!

Reove the shield tube from around the bundle of wires and visually inspect for an broken wire