OK, I got my FM modulator ready to be hooked up. But I have a gray wire that says "Play on +12V" What is this for? Which wire do I hook it up to? Thanks.
Actually, you will want to wire the modulator to a switch so that you can turn it off when not in use. When the modulator is turned on, you will notice that it weakens your FM radio reception and causes interference on some channels. You will want to turn the modulator off whenever you are listening to the radio!
I tried having my modulator connected to the PC, bu toften I would be listening to MP3s then want to check news on the radio without shutting down the computer. I'm not sure if all modulators are alike, but my radio is almost useless whenever the modulator is turned on. I have put a switch on the modulator so that I can turn it off withouyt turning off the PC, and this has been a good solution for me.