69 Valiant Radio Help

I appreciate your reply. Here's what's got me....

I removed the harness from my old car's(1989 Chevy S-10 Blazer) radio and there was a split-off piece with two wires---the yellow(power) and an orange wire which terminates back to the harness(no connection on the radio side). It seemed like a dead wire, so I clipped and capped it, but why is it part of a GM 89 S-10 Blazer radio connection(my old truck that it was hooked up to)?

I spoke with my friend who installed radios in multiple cars including a 1967 Camaro and he couldn't visualize what the orange wire from my old GM harness was for( as I said--it dead-ends to nothing on the radio harness side...).

There are 4 wires that fall from my Valiant's dash--2 are from the front speaker-green and green/black. The other two are red and orange---from what I read from my earlier post replies--red is power and orange provides light to the unit when the car's headlights are turned on(illumination).

My Kenwood MP522 manual says that the red wire from the RADIO HARNESS is for the acc connection to newer cars. If there is no acc connection on my car(obviously) connect it to a power source that is active with the key forward or else it drains the battery. I didn't even connect this wire, just capped it. But this would not affect it as far as turning on---correct?......I guess I need to test my red wire from the dash(battery/power) and make sure it is still hot. I don't know what else to do.....Any ideas would help. Thanks.