Quick question about aftermarket radio?

You could hope its a wiring issue. Pull the unit and check your harness. If it's not that, you got a POS.

If it was a short, you'd be going through fuses. Sounds more like a bad ground or power connection. Could even be inside the radio.

If you plan on swapping radios, don't plan on putting your old one (if it's stock) back in, unless you have the code for it.