Audio Systems: AM radio signal problem, signal problem, shiny thing

Question
Hi,
I have a 2003 Honda Civic that i recently changed the Head Unit in.
I am having AM radio reception problems and have switched out severall
different Units and they seem to still have that same problem. With
FM/CD everything is fine. with AM i would need to turn the volume to MAX
to be able to hear the station properly. is this a car problem? or HU
problem? There are no Amplifiers. thankyou

Answer
If you have switched several Head Units then we can safely rule that out which leaves the 'twig', that shiny thing sticking up from the wing (fender). Have you checked for a disconnected lead along its leangth? Is it an amplified aerial and it's not getting 12v signal from the head unit?
Is it well earthed?
Gotta be the twig.
Let me know and don't forget the feed back,
thanks,
Peter