Audio Systems: No AM reception, chevy malibu, captive nut

Question
My 1997 Chevy Malibu's factory am/fm/cassette am reception stopped working some time ago, although FM was fine.  Just recplaced with aftermarket radio/CD. Once again, FM is fine but only static on am.  Is this a antenna problem, lose connection somewhere?  Thanks very much!

Answer
Mike,
The antenna for the stereo has to be in very good condition in order to receive AM stations. If the shield isn't grounded well at each end, the antenna will pick up all kinds of unwanted noise. On many vehicles the AM radio will pick up noise from the engine and from the engine computer even if the shield is OK. The most common area where a defective connection can be found (if you have a fender mounted antenna) is where the antenna is bolted to the fender by a large captive nut. On the bottom side of the antenna, gripper fingers will corrode and the ground connection will be lost, use a large pair of pliers and tighten the nut. If this doesn't fix the problem you should replace the complete antenna and wire from the fender to the stereo.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net