Hi all. I was wondering could I seek some more of your sage advice!

Ive purchased a mk7 fiesta that was cat N (damage to the driver side wing that has now been fixed). 
 

the problem is with the audio though. When you turn the key to position 1 (electrics on but car not on), the radio works. When you start the car, the radio is still on the radio station, volume goes up and down on screen. But nothing from the speakers! 
 

After checking fuses and replacing them, no change. But then out of testing (and frustration) I banged the door card and the sound came back on!!

took the door card off and checked all connections to the speaker and they look ok. Nothing nipped or stretched. But still when you start the car, you need to bang the speaker to get the sound to come out. 
 

could the speaker be duff or something else more strange? Could it be the vibration of the startup that the speaker shut off as a safety?
 

Any help would be greatly appreciated! 

Once the audio works how does it stop again

34 minutes ago, Danny cj said:

Once the audio works how does it stop again

Just when the car is turned off and then restarted again. Then when I thump the speaker, it all works again. It’s so strange 

Sounds like the speaker or wiring is short circuit..are you able to remove door panel and disconnect that speaker and test

Definitely seems to be wiring. I took the speaker out and tested it. Getting good ohms and also did the 9v test and it’s working. 
 

i’ll try trace back wiring tonight and see what I can find 😊

With the speaker removed ditto the radio work ok

No. It still did the same. It works when in key position 1 but then goes to no sound when the engine turns on. it didn’t work again until I plugged the speaker back in and thumped it again. 
 

I tested the battery too and it’s actually fine. 
 

makes me think even more that it’s wiring