This is a 68 Radio converted to I believe Pioneer.
I bought it years back and I am getting sound but not so great.
If anybody recognizes the harness leads please ID them.
I recall a vendor was converting AM to Pioneer based high Watt Super Tuners.

Red and Orange are on a Factory Plug for power and light.
I got it powered up and lit with ground through Chassis.

Grey and White sound pretty good together.
Blue and purple make noise but sketchy.

Could this be a common ground?

Brown does nothing.... for speakers

Thanks in advance.....