Every time I turn on my radio, especially when I use the FM Transmitter for my iPod, I there is a loud static that corresponds to the RPMs of my engine. It sounds to me like the antenna is picking up interfearence from the ignition system. 1. What is the cause of this? 2. How can i fix it?
I just bought this antenna brand new from GM as a replacement(not sure if it's the original kind that came with the car or not) and installed in myself.

 

That is most likely noise from your alternator. It can point to early signs of your alternator failing, but could probably be cleared up with a good quality noise filter.

One question when you are using the iPod, is it or your FM transmitter plugged into your cigarette lighter socket?

First place to troubleshoot alternator whine in a system is looking for a poor ground.

 

Do you mean a ground for the electrical system or for the antenna?

 

grounding of the audio system

 

Did the noise start when you replaced the antenna? Or did you replace the antenna to try to stop the noise?

 

Actually, the noise started about 3 weeks after I replaced the antenna. The antenna worked great for a few weeks, then started getting worse.

 

I still think it sounds like the beginning of the end for your alternator.

 

If you unplug the ant. is it still there?

 

couldnt you just listen to the radio with the car off to see if it's the altenator?

 

No, it only happens when the engine is running as he said (or implied). My radio actually has a static fit when I lower or raise my driver side window. Its not a real hassel since I don't play with the window the whole time, just kinda wierd haha. (Power windows btw)

I heard a long time ago that (IIRC) resistors were put into the spark plugs to reduce radio interference. Maybe it wasn't a resistor, maybe it was a capacitor or something, however those deal more with DC noises.

 

To make it clear, it ONLY does this with the engine running, it sounds fine with the engine off. Just curious, but how can the ateernator make that interfearence when it is so far away from where the antenna is?

 

The alt. would be putting the noise ON the B+ line. There no noise when playing CDs?

 

No noise while playing CD, only when playing the radio.

 

Kinda sounds like some sort of wierd ground loop. Next I would probably try taking the ground wire from the radio and making sure it is attatched to a solid chassis ground.

If you have access to a volt/ohm meter, I would measure resistance between the center pin of the antenna connector and the outside ground fingers and make sure the antenna isnt shorted out. also measure from the outside ground fingers of the antenna connector to the car body to make sure it has a good ground.