i am loosing signal when i touch or hit under the aerial or whe i open the trunk

i wan to kno where can i check the cable conected to the aerial so i can fix that or buy a new one ....

sorry if i am askin a lot of question this is my first car that i bougth and i like it much

an i want to fix everythin in my power no matter cost

if i hve to go too the uk i will go to buy part

i forget to ask when its not raining and i am cleaning the back windows the wiper keeps active

that i have to turn out the car to stop it