Our 2013 Elantra's radio and nav system will not make any sound. I checked the fuses marked amp and they were good. Is there anything else to try?

This issue sounds like it could be related to a problem with the ground connection or the reverse gear sensor in your 2013 Hyundai Elantra. The radio may be losing power when the reverse gear is engaged and the car is on a hill, causing it to cut off and then come back on. Here are some things you can try:

1. Check the ground connection for the radio. Make sure it is tight and securely connected.
2. Check the wiring for the reverse gear sensor. Make sure it is properly connected and not damaged.
3. Inspect the reverse gear sensor itself to make sure it is not malfunctioning.
4. Check the voltage of the battery, low voltage can cause the system to shut off
5. If none of these solutions work, it is recommended to have your vehicle inspected by a professional mechanic.

It is also important to have a professional diagnose this issue as it could be caused by multiple other electrical issues and a proper diagnosis is needed to find the root cause and prevent further damage to your vehicle.

This will be tedious and time consuming, but it is the only way to find the problem. Disconnect the negative battery cable and connect a multimeter leads set for 10 amps and read the draw on the system. Now remove each fuse one at a time. If the draw is still there. put the fuse back in and move to the next one. Do this until the meter reads zero. That fuse will identify what is causing the problem

You need to reset the sound system. I did it by taking out the fuse for the audio system marked "amp" and I did another marked "A/V system" (you'll have to read the owners manual for the the right fuse, but I'm guessing it's the same - I have a Santa Fe). I understand you can also reset the system by using a paper clip or ballpoint pen and pushing in the tiny recessed button by the CD player. I haven't done that, but if it works, it's certainly easier than taking out the fuses. Either way, wait at least 15-20 seconds (before releasing the button or replacing the fuse). Note: you will lose all your radio presets, so you may want to write them down.

Did you check the radio, or stereo system? are the lights on the stereo system still on? If not find the defective fuse.
When you still see lights, still the power amp can be defect or its fuse. Or just a bad contact in the power cable going to the amplifier.
So many things that can go wrong. If you don't look under the hood, you won't find a cause. As a tech it could cost me half an hour to fine what is wrong when I had to investigate it myself.
Almost impossible to pinpoint the exact cause. I only can give hints were to look.

when did this start? Was you experiencing any kinds of Bluetooth issues or streaming music issues or plugging into the car and playing music? Do you have the Technology package?

There is a reset button on the to the left of the phone button on top of the navigation LCD

My 2011 Elantra radio turns on but no sound. fuses are good. It use to only happen if I put the car in reveres to quick. I will take to dealer for warranty.

In the fuse box under the hood, fuses 3, 6, 7, 10, and 12 are all directly related to the sound system. In the trunk, fuses 3, 6, and 7 are also directly related to the sound system. Please check all the fuse.

And also unplug the CD changer's power and fiber cable and then recheck the radio.

there are alot of fuses that control radio/ nav system with a few computers, if you use a scan tool to scan computer it will give you codes of what is wrong, anyway here are the fuses i found, left side of engine compartment # 26 is one fuse then left side of dash theres another fuse/relay box and at #16 and #1 are two more fuses then there are more fuses for modules and computers than run that system, good luck hope this helps.

Sounds like an amplifier issue. Check the fuses that run the factory amplifier, if not a fuse, then most likely a bad amp.