mp3 FM mod question

I've been using my xm radio to listen to my mp3 player through my factory radio. I don't have xm anymore so I took it out (along with the xm fm mod) and put in a regular fm modulator and now there's a loud constant wine. Now I'm wondering if there is a way to use the xm mod without the xm radio, since it sounded fine before. I was thinking maybe using an on/off switch for the power wire of the xm radio. Any suggestions?????

I didn't know XM receivers had an audio input. I'd like to see/hear the details on how you got this to work. It sounds like you are getting noise or there is a problem with the modulator itself. There's no reason why it shouldn't work or for you to do any "mods" to make it work.

That wine you're hearing is coming from the electrical system. You can buy inline filters that will reduce or eliminate the wine completely.

There actually isn't an audio input. What I did was plugged my mp3 player up to my xm fm modulator input, and I had to power on the actual xm radio so it would turn the fm modulator on. So, what I was wondering is if I took the power wire coming from the fm modulator to the xm radio and connected a switch to it. It does sound confusing.

I'm probably going to get the inline filters I was just looking for an easier way around all these wires I keep adding so everything will work right. I wish now I would have just bought a new CD player with a usb input and rca input's....

It sounds like the XM radio's fm modulator is of a higher quality than your standalone fm modulator.

One of those filters should take care of the whine.