How can the volume work but the sound doesn't? They're the same thing. You see why I'm confused. What kind of FM transmitter are you referring to? The only thing I've ever heard of is an FM modulator that takes the audio from a CD changer or a satellite receiver and puts it onto an FM frequency that the radio can pick up just like any other radio station. The radio's FM and audio circuits have to be working for those modulators to work. To say that another way, you have to be able to pick up and listen to FM stations. To go even deeper, all FM circuits feed into the AM circuit in almost all radios, so, except for a few rare cases, if the FM works, the AM will too. You CAN have a dead FM system while the AM is still working.
It just occurred to me, do you have a volume level on the radio's display, and THAT'S what you mean is working? That would make sense. If that's what you're saying, it sounds like you simply have an issue of no sound. That can be caused by a loss of the 12 volt memory circuit. Loss of that circuit, due to a blown fuse, affects various radio models differently, but on almost all of them that will include, if the clock works, it will reset to 12:00 or 10:00 each time the ignition switch is turned on. If the clock is always at the correct time, that memory circuit should be okay. That circuit is usually tied in with some other system that is always live such as the horn, or more commonly, the interior lights, so you'll need to check for a blown fuse is one of those circuits is also dead.
You also have to consider whether the car has a factory-installed amplifier. If it does. Check for a blown fuse for that. A problem inside the radio can also cause it to fail to tell the amplifier to turn on.
Tuesday, May 19th, 2015 AT 7:27 PM