Audio Systems: AM radio signal problem, signal problem, reception problems

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
hello:
car problem
or antenna problem  there are to style antenna in this vehicle the normal antenna that is moun on the roof or the antenna in the back window  if in the roof the antenna or the cable can be defective and needs to be replace  
if the antenna is in the back windo there is a module for this and it is behind the plastic this module uses power check the conections
good luck