Radio Reception Bad - Only When Car Running

As stated in the topic, I have bad radio reception only when the car is on. When its running, I can pick up only the 3 or 4 strongest channels with near-perfection. When the car is off, my radio is superb.

It is a '95 Chevy Cavalier with an aftermarket stereo. It has new plugs, new plug wires,alternator,starter.. so these should not be the culprits (some people have previously suggested such components).

BTW, the sound does not increase/decrease w/ engine speed, and I cannot associate it with any other device's operation. It is like constant static that intermittently fades and comes back.


Anyone have any ideas? Make sure all the grounds are clean and tight. way2old wrote:Make sure all the grounds are clean and tight.


Which grounds are you referring to, considering that it only occurs once the car is running? When did the problem start? Right after installing the new stereo system? What too old is saying is check your original wiring, radio ground, antenna connection, etc.., stuff like that. You may need a wiring diagram to check for proper installation. Add on stereo's have caused more driveability and electrical problems to me over the years than anything else! Nothing scarier than seeing a big 8-10 gage wire running to the battery positive post, with no curcuit protection then under the hood or thru the door jam! Also sometimes, wires are cut or left unplugged in the dash, that are neccessary for noise suppression? los losmaster wrote:When did the problem start? Right after installing the new stereo system? What too old is saying is check your original wiring, radio ground, antenna connection, etc.., stuff like that. You may need a wiring diagram to check for proper installation. Add on stereo's have caused more driveability and electrical problems to me over the years than anything else! Nothing scarier than seeing a big 8-10 gage wire running to the battery positive post, with no curcuit protection then under the hood or thru the door jam! Also sometimes, wires are cut or left unplugged in the dash, that are neccessary for noise suppression? los


I've had this problem for as long as I can remember. Of course, its had an aftermarket stereo system of some kind as long as I can remember.

It can't be the antenna connection, because like I said, it works perfectly when the car is off (key in the run position). Radio ground.. same thing there I would think. The only thing I could conceive going wrong in that circuitry is a bare wire being exposed to some RFI from another component when the car is on... unless a bad ground could cause a similar problem???

Nothing has been left unplugged and I can't imagine anything is cut either. I imagine its RFI coming from somewhere... just don't know what though. I guess I am going to have to do what another site suggested, which is to find a cheap AM radio and aim it around at various locations of the car to attempt to isolate the offending device. BNut83 wrote:losmaster wrote:When did the problem start? Right after installing the new stereo system? What too old is saying is check your original wiring, radio ground, antenna connection, etc.., stuff like that. You may need a wiring diagram to check for proper installation. Add on stereo's have caused more driveability and electrical problems to me over the years than anything else! Nothing scarier than seeing a big 8-10 gage wire running to the battery positive post, with no curcuit protection then under the hood or thru the door jam! Also sometimes, wires are cut or left unplugged in the dash, that are neccessary for noise suppression? los

I've had this problem for as long as I can remember. Of course, its had an aftermarket stereo system of some kind as long as I can remember.

It can't be the antenna connection, because like I said, it works perfectly when the car is off (key in the run position). Radio ground.. same thing there I would think. The only thing I could conceive going wrong in that circuitry is a bare wire being exposed to some RFI from another component when the car is on... unless a bad ground could cause a similar problem??? Important to remember that CDs play fine all the time, crystal clear.

Nothing has been left unplugged and I can't imagine anything is cut either. I imagine its RFI coming from somewhere... just don't know what though. I guess I am going to have to do what another site suggested, which is to find a cheap AM radio and aim it around at various locations of the car to attempt to isolate the offending device.