Alternator noise in the radio HELP !

[Nos]

For some reason im getting alternator noise when im on FM or AM BUT NOT on CD. I have a pioneer premier mp470 cd player . I took the stock radio and stuck it back in and same problem so its not the radio . Im grounded on the stock ground so i tryed a different ground , i ran a 14 gauge wire to a steal beam under the dach and no luck it still does it . Now i noticed something , when i unplug the ground wire the radio still works ? it that normal ? The only thing i did'n try was to run a fat ass wire straigth to the battery . Im thinking the radio is grounding from the antenna but from where ?? The antenna wire seams fine .

I have no amps or aftermarket speakers . So im sorta out of ideas to try . Do i need an antenna filter or a power filter or something ?

Please help me ! thx

 

[1sty]

The stock system should work with no noise.
What else is in the system, amps, aftermarket speakers, ect?

If you can remove all modifications and it still does it, my guess is that the antenna wire is pinched or may even be grounding out somewhere.

 

[Brian MP5T]

Ground

 

[1sty]

Ground

If there is nothing else in the system then it is not the radios groud in question but the antennas

 

[Nos]

If there is nothing else in the system then it is not the radios groud in question but the antennas

I have no amps or after market speakers . When i unplug the ground the radoi still run , i checked the antennna wire from all visible places and it looks good . Maybe I need to try another antanna .

 

[1sty]

I have no amps or after market speakers . When i unplug the ground the radoi still run , i checked the antennna wire from all visible places and it looks good . Maybe I need to try another antanna .

Is it the factory antenna wiring or did you replace something?
I am curious, if you dissconet the ground and the antenna wire, does the radio still play when not mounted in the dash?

 

[Nos]

let me try this today .

 

[Nos]

OK uptade the radio DOES not work when the antenna is unpluged . Thats means that my radio is grounding trough the antenna for some reason . Now im gonna try with unplugging the antenna trougth the other connector from the driver side . If it still does not work then its from that connection to the antenna . rigth ?

 

[Nos]

Ok uptade again lol , im gettin closer . IF i plug that antanna plug on the driver side the radio works if i unplug it it does NOT work . That means the radio is grounding from the antenna from the driver side plug to the antenna . rigth ? so i need a new antenna ?

 

[chaosProtege]

antenna wire

 

[1sty]

Ok uptade again lol , im gettin closer . IF i plug that antanna plug on the driver side the radio works if i unplug it it does NOT work . That means the radio is grounding from the antenna from the driver side plug to the antenna . rigth ? so i need a new antenna ?

WIll the deck stay powered up if the ground is connected but the antenna is not?
Obviously the radio will just have static.

 

[Nos]

WIll the deck stay powered up if the ground is connected but the antenna is not?
Obviously the radio will just have static.

Yes the radio works if the ground is plugged and the antenna unplugged . So that means im ok when im using the cd player since its not using the antenna .However when i use the radio it grounds from the intenna and creates static with the stock ground ? . So the conclusion would be to change the antenna or at least try a new one ? I don't see any other possibilities . What do you think 1sty ?

 

[1sty]

Yes the radio works if the ground is plugged and the antenna unplugged . So that means im ok when im using the cd player since its not using the antenna .However when i use the radio it grounds from the intenna and creates static with the stock ground ? . So the conclusion would be to change the antenna or at least try a new one ? I don't see any other possibilities . What do you think 1sty ?

The antenna always presents a groud for the system so your grounds appear to be working normaly. What may be happening is that the antenna is grounding where it should not.

The real test of if it is the antenna wire is to unplug the antenna from the radio and turn the radio on and listen for alternator noise. Obviously you need to go for a drive to do this and you should turn on your lights when checking noise as it will make it more audible.

 

[Nos]

I unplugged the antenna on the drivers side ( for now ) and turned the radio on and from 96.xx to 99.xx fm i hear no alternator noise whats so ever . From 100.xx ro 106.xx i hear some but barely any . I had the lights on , A/c and defrost . I will try unplugging from the radio tomorow . Could it be my alternator going bad or something ? So its normal for the antenna to ground the radio ?

I will see if i can try another antenna . Now I don't see where the problem could be from . (attn)

 

[02BlueP5]

I unplugged the antenna on the drivers side ( for now ) and turned the radio on and from 96.xx to 99.xx fm i hear no alternator noise whats so ever . From 100.xx ro 106.xx i hear some but barely any . I had the lights on , A/c and defrost . I will try unplugging from the radio tomorow . Could it be my alternator going bad or something ? So its normal for the antenna to ground the radio ?

I will see if i can try another antenna . Now I don't see where the problem could be from . (attn)

check your plug wires.

 

[Nos]

check your plug wires.

All antenna plugs are fine , radio plugs are good aswell . 1sty help !

 

[chuyler1]

Since you have isolated the problem to the antenna...perhaps you simply need an antenna isolator.

http://www.autobarn.net/metawanfl.html

 

[1sty]

I would ceck the connection at the antenna and see ifthe ground is fraid ormessed up.
It is possible that the alternators rectifier bridge is F-d or the battery is not all there anymore and is not filtering out the mild AC ripple the alternator puts out.

You can have each tested at mostauto parts stores or garages.

 

[02BlueP5]

All antenna plugs are fine , radio plugs are good aswell . 1sty help !

lol, i meant the spark plug wires.

 

[Nos]

If it would be the alternator it would do it aswell on CD ? How to i check the ground on the antenna , when you unbolt the antenna the antenna wires goes rigth into the plastic thing . As for my spark plug wires well they are fine cause my car does not bug .