Identify wiring & 3 prone connector, located under driver side dash

[beardogc20]

Can someone help identify what this connector could be used for?

I recently purchased a 1976 C20 scottsdale. The wire starts from the fuse box (15a) then continues to a online fuse and ends with a 3 prone connector. From connector a ground wire (not connected)

Thanks

 

[legopnuematic]

CB radio or similar power cable.

 

[beardogc20]

After your suggestion and a quick Google, it definitely does.
Thank you legopnuematic

 

[Radiohead]

Yup, Uniden CB power cord. Fits quite a few of the older models.

 

[beardogc20]

Thank you Radiohead

 

[bucket]

Yup, Uniden CB power cord. Fits quite a few of the older models.

What was the third terminal ever used for? I've only ever seen two wires in them, power and ground of course.

 

[Radiohead]

Not sure Bucket, I've only seen two wires as well. Maybe a polarity scheme?

 

[Tonimus]

What was the third terminal ever used for? I've only ever seen two wires in them, power and ground of course.

The third pin, when used, was for ignition power. Battery/Ignition/Ground in varying order, almost always with the ground pin on the single side, IIRC.