AUX input jack for 67-72 AM radio

[lsversaw]

This is absolutely the cheapest/best way to connect any music player or phone to your audio system. The only shortcoming, if there is one, is that you'll hear mono, not stereo.

If your radio isn't working, you can just connect an aftermarket amplifier between your phone and original speaker. You can get a name-brand, highly-rated amp for under $100.

If you go the route of an aftermarket amp, you can also wire your original-radio on/off/volume control to manage on/off and volume through the amp.

I can add all sorts of features to original radios -- aux input, Bluetooth, USB, FM stereo, more power, pre-amp outputs -- but I realize that it's expensive compared to DIY options like the one descibed here, and not the best option for everyone.