Blue radio wire?
 

Hi folk's. I picked up an original am/fm delco radio yesterday. I pulled it out of a 1971 pickup with no windshield. Knobs are a little rusted but do turn. The slider moves but the display does not change. Does it need power for that to work? Also from what I found online the yellow wire off the back is to power. The black/green and green go to speaker. It has a blue wire that comes off from the right side dial. I have no clue what it goes to. I want to put power to it see if it works. Thanks for any help. Russ

Re: Blue radio wire?
 

Do you have any pictures of it? Are you sure it is a pickup radio? That wire might be for a rear speaker from a passenger car. Slider does not need power. Sounds like it has rust inside the radio keeping it from moving. This kind of sounds like a passenger car radio, that come with a rear speaker fader knob.

Re: Blue radio wire?
 

Here a pictures.

Re: Blue radio wire?
 

Do you have a pic of the face?

Re: Blue radio wire?
 

Here's the front.

Re: Blue radio wire?
 

I agree that the blue wire is probably for a rear speaker. I have a van AM/FM that I modified to look like an original truck radio. It has the blue rear speaker wire. I mounted the van 6X9 rear speaker in a spare factory console with the speaker pointing out an opening in the back. Certainly doesn't sound like a modern stereo system, but the sound is much better. Not all van radios had this provision. I have another van radio without the blue wire.

Pictured below for reference are the unmodified van radio, the modified van radio and speaker mounting.

Re: Blue radio wire?
 

Thank you for the help. Russ