I have a 2002 Dodge Neon (yes… don’t make fun of it). My radio will play for about 15-20 seconds and then shut off. I found if I keep pressing buttons before the 15-20 seconds I can keep the radio on indefinately. The dealer told me the Radio was shot to get another… (I did)… and the new radio does the exact same thing. Is there a service bulletin about this? Is there a capacitor or something that supports the speakers?
Can you determine whether the radio is still receiving power when it “cuts out”? On some cars, there is a separate power feed to keep the memory alive for the station selection buttons. I suppose it is possible that somehow pressing these buttons feeds the radio from this power source.
Try operating the radio with the ignition key turned to the accessory position. If the radio doesn’t have this problem of cutting out, then the problem may be in the ignition switch. If the radio won’t play at all when the key is turned to the accessory position, it may also be the ignition switch.
I suppose that the radio may not be grounded properly to the car chassis. Bad grounds can cause all kinds of problems.
Was the replacement radio a new radio? It is hard for me to believe that two radios would have the same problem, but I suppose it is possible. If you had someone install the replacement radio, I would go back to that person.
If the radio is on, but the speakers cut out, then either the wiring to the speakers is defective or the radio is defective.
This is a strange problem. I suggest you check the power input to the radio to see if that is ok and holding up when the radio turns off.
After more thought about your problem, I think that the radio is not making a good ground connection. When you push the buttons, you are jarring the radio so that the ground connection is made. Make sure the braces that hold the radio are tight. You might want to run a wire from the frame of the radio to a good ground point and see what happens.
Did you put a factory radio? Not much to it. Probably bad ground or broken pwr wire. There are a couple fuses you can reseat.