Need AMFM Wire Connection Help Please

[DANL]

Hey members, I need help with hooking up my AMFM. I remember seeing a post earlier on wiring connections for AMFM. I did search but could not find it.
I have radio harness with red wire, black wire and green wire.
I assume red is power supply and black and green wires go to speaker. There is also a blue wire, with plug, that comes out of radio. I am not sure about the blue wire.
Can someone help me please?
Thanks in advance.

...Dan

[Hooter]

um is that the dimmer wire?

[DANL]

Originally posted by Hooter
um is that the dimmer wire?

Hey Hooter, thanks for the response.
But the blue wire actually comes out of the rear of radio.

...Dan

[Hooter]

hmmm, did the radio come out of a truck, Im thinking it could be power antenna, if it was out of a caddy or something, I cant really think of what it could be, unless it is a ground strap, Does it look original?

[cochino12]

The blue wire should be for amp turn on or pwr antna, If it's an aftermarket radio

[DANL]

Hey Hooter/cochino12, thanks for the response.
It is a van radio. I may try one of the local Chevy dealer's
for advice.
I will keep you in the loop.

...Dan

[Hooter]

If it came out of a van, it might be for an optional rear speaker.

[72c10]

I always thought that blue was for back lighting on stock radio's

[DANL]

Hey everybody, I got it installed. I left the blue wire disconnected. Everything works, including the back light.
I guess the blue wire is optional.
Thanks for your help.

...Dan