Car radio suddenly has bad FM reception.

car starts, runs and drives perfectly?
AC or heater blower works on high?
head lamps work fully and brightly.?
tail lamp (park) all glow? ?
brake lamps work and are bright.
check fuses?
look for connections to the radio loose or damaged

AM Radio dead means the antenna is missing wires to it bad. or missing.
FM may work say on 1 stations if the stations is like 5 miles away, all stations that are under say 25miles must work or the antenna is bad. FM, and vastly farther for AM.
we do not know where you live( a town) so can never guess
what stations are in range to you. see?

Sounds like an antenna issue, any radio installation shop should be able to check that for you.

There is no Am anymore only FM, you may pick up bit but nothing good!!

You will need to pull the radio out of the dash and make sure the antenna is still pluged into the unit. If the antenna is in the windshield make sure the glass is not broken, and the wire broken. If there is an external antenn, you need to check the connection at the bottom of the antenna, and the wire is good between the antenna and the radio. Has any new items been mounted recently, the screws could have damaged the coax.
Rian

Most radio reception problems that occur only while the car is running are caused by damaged diodes in the alternator. It can be difficult to diagnose this since most dealers and repair shops will not disassemble the alternator to test the diodes. If you can find a shop that rebuilds alternators they can test for bad diodes and replace them if necessary. Hope this helps.

If you still have good strong AM reception, chances are that the FM receiver portion of your radio has failed. Radio repairs are usually as or more expensive than replacing with an aftermarket unit. You can either find a direct factory replacement in a scrapyard or just buy an aftermarket radio (with an adapter harness) and install it.

try takeing back out and see if the conection on the back has come off if not have a look at the conection its self

you can try a AM/FM antenna booster if you know how to get to the back of the radio. Otherwise the radio ground needs to be checked out and the antenna ground would need to be tested to see if there was corrosion on the antenna base or the connector to the back of the radio. On some cars the antenna is located in bad area and they don't get the signal boost off of the cars ground plane The more reflective surface you have on the car the more radio waves will bounce back and increase signal strength. Also Depending on atmospheric conditions and skip conditions sun spots and other natural occurring things can cause poor reception. The signal booster is about $10.00 at any radio Shack or any auto parts store. Hope this helps.

check radio antenna. could be loose connection or antenna missing or broken.

This would be a bad connection. In this case you have 2 connections to check, 1, where the antenna wire connects into the back of the radio, and 2, where the antenna wire connects to the antenna. Most likely, it would be a loose connection, snap the wire back into the connection and use electrical tape to hold it into place, or if you want to be more fancy you can use pliers or a pick to make sure the connection stays put.