Grand Am radio removal: Pop out gray plastic trim around radio. Remove around four 7mm bolts (9/32" also fits perfectly). Slide radio out.
The antenna is a thick, black cable, separate from all the other wires. Be sure that it is secure. Make sure the antenna mast is tight. Use an adjustable wrench to tighten the mast. Take care that the wrench doesn’t nick the paint as you turn.
If you get a lot of engine noise with AM radio, this is a hint that the antenna isn’t properly grounded to the car’s body, or that there’s a break in the shielding of the cable. It will probably take professional troubleshooting to find the exact nature of the problem. Or you could just replace the whole thing.
Delco (General Motors) radios have the best reception I’ve ever experienced—if yours isn’t doing well, something is definitely wrong.
If you decide to install an aftermarket radio, figure on about $50 (full retail) in parts. $16 for the mounting kit, to make the smaller aftermarket radio mount in the large GM opening. $16 for the wiring harness adapter, for the main power/speaker connections. $11 for the antenna adapter. (All GM cars from the late 80s/early 90s on up DO have a unique antenna connection.)
used GM tape decks can be obtained very inexpensively–you should pay no more than $25. Check eBay or local junkyards. Or I can find you one if you have trouble. There are many, many different styles of factory GM radios, with different backlighting colors, knobs, features, et cetera… if the back of the new radio has the same plugs as yours, and you can transfer the mounting brackets from your old radio to the new one…you’ll most likely be all set.
If you can obtain/borrow a long automotive antenna extension cord, do this test: Using the extension, operate your radio, but using the antenna mounted to a buddy’s car…then try your buddy’s radio using your antenna…you will quickly figure out which item is broken.
If you need to replace the antenna: If it’s on the rear quarter panel, peel back the trunk carpet and all is self explanatory. If it’s on the front fender, it’s not even worth doing.
Radio Shack sells an easy do-it-yourself windshield antenna for $5—it’s essentially a roll of Scotch tape with a metal wire in the middle, mated to an antenna plug. They’re easy to install and work fairly well. As Radio Shack is discontiuning their car stereo stuff, this antenna may be hard to find.
Most replacement antennas will have a standard plug that will not go into your GM radio–again, an adapter is needed.
If you replace the radio with an aftermarket one: Metra 40-GM-10
If you replace the antenna with aftermarket: Metra 40-GM-20
If you install an aftermarket radio AND antenna: none needed
You can look up these parts at www.metraonline.com. Also, www.scosche.com or www.americaninternational.com. Most car stereo shops use one of these “big three” kit manufacturers.