2005 chevy cobalt.radio don't work.change int.fuse.isthere another fuse

Here's a question, is that the original equipment radio or is it aftermarket? If it is an aftermarket or upgrade, optional radio, the chances are good that you will need a special code to access the radio and get it working. The reason the code is needed is that it is part of an anti-theft feature that many radio manufacturers have used. Sometimes, in fact, new-car manufacturers have implemented it as well. Take Honda, for instance. If you pull one of the radios out of an older Accord and to swap it, you will find you need a special radio code to get things working, even minimally. You can obtain the code from the manufacturer and get the procedure for inputting it so that you can turn the radio back on. A similar method is used by aftermarket manufacturers.

I have not heard that Chevy had implemented such an anti-theft program on the 05 or 06 Cobalt (I owned an 05 Cobalt), but it's always possible, especially on a model with an upgraded radio/sound package. I would check with Chevy to see if that's the case on the Cobalt, otherwise, it's likely that the radio is shot and it's time for a new one.

Check the cigarette fuse, Sometimes it's the memory of the clock on the radio and if you pop that from a cell phone your radio won't work..