[Thomasluke7899]

You need 4 things for the radio to power up.
A working radio.
12 volt source.
Switched 12 volt source.
A proper ground.
It sounds like you have 2 of those.
A ground for sure.
A working radio.
You will a digital multimeter to read the DC voltage in the harness.
Find what you are missing and then find a way to get to the radio.

 

[Thomasluke7899]

Then check your ground.

 

[Thomasluke7899]

If it has all three then you have a magical non-working radio.

 

[Thomasluke7899]

If could of would of then I'd be rich. You need to verify.