Hi, can anyone help (I have a 53 seat leon – diesel)?

The radio was playing up, I took it out and connected a bit of loose cable to the aerial slot and it worked perfectly. So…. I’m guessing its a problem with the car’s aerial cable. I unscrewed the solid aerial on the top and attached the loose cable to the metal screw and it didn’t work. I assume this must mean there’s a fault between the cable that plugs into the back of the stereo and the other end the attaches to the roof aerial.

Does anyone have experience of this before? Do you know how I might fix it, or at least expose the cable?

Many thanks in advance.