Hello Lee,
You may want to check to make sure your device has the latest software update. Sometimes if your device lacks the latest update then it may not operate correctly or even at all. Try downloading Garmin Express on your computer, plugging in your device and updating it that way. Another possible explanation is that your device could be overheated. Prolonged exposure to direct sunlight can overheat the battery and cause your device to not work properly. Try taking your device inside and letting it cool down and then try again. If neither of these work then it may be because you have a faulty battery that needs to be replaced. You can consult this troubleshooting page to help you walk through this process [[Garmin Nuvi 265WT Troubleshooting|here]].