am/fm/cb antenna

[Axle]

Seems everytime I look at my new '81 GMC it comes up with something new to taunt me with.

This time, it is the cable routing for the am/fm/cb antenna. Never touched one in my life, maybe seen one or two of this style on finished trucks, and now I have one. Problem is, I can't find the other end, or where it enters the cab (it is not attached to the radio, I only have the short antenna "joiner" attached to the radio along with a paperclip antenna hanging under the dash.

The cable coming from the antenna is there, and it routes INTO the cowl just under the corner of the windshield on the passenger side (red line in 2nd image). It does not follow the typical route of going into the engine compartment and through the firewall. There is maybe 6-8" of antenna wire exposed from antenna to where it disappears into the cowl.

I have the dashpad out, glovebox out, only thing I have not done is ripped off the pad that is glued to the firewall, or pulled out the plenum. I have found no holes, I have not found any cb/radio antenna splitter (unless its well tucked behind the plenum out of reach). Weather started turning, so I did not pull off the cowl cover to see in there.

Is the cable going into the cowl at the base of the windshield corner factory for this style antenna? If it is, where does it enter the passenger compartment? Or have I discovered another previous owner hack that was never finished?

Alex.