Power antenna wiring?

[Chuck944]

I am replacing the original with an aftermarket antenna. The existing wires are red, white and black. Black seems like ground but the other two show 12v only when the radio is on. Is that right? The new antenna needs 12v that's always hot, do I have such a wire?
Thanks

[Inferno_Rob]

Yes. One of the wires (the red ) is constant hot while the white wire is positive when the radio is on but nothing when off (radio switch / ant. wire)
I just completely rebuilt my factory power ant. for my 83 and it took really no time at all except for removal and installation.
In most cases the contacts on the commutator and the power ant. motors endbell become a bit corroded so if you know a bit about electric motors you too can get your power ant working again.
In mine I removed the electric motor and then the endbell from it, cleaned the brush hoods and added a bit of lube to them as well as cleaned the brush shunts while being carefull not to loose the springs behind the brushes.
Clean the brush faces themselves so the contact with the commutator is good again.
Then I took some emery cloth to the commutator to get the copper surface shiny again for stronger contact with brushes.
Finally before re-assembly checking continuity between the end of the wire to the brush hoods. In mine I found one side had no continuity at all and it was the side with what appeared to be a fusable link ( which I think was really just an overload breaker in small scale) and after opening it to see what the problem was I noticed it had been long since corroded and contact was impossible.
I solved this by soldering the link together making it a solid link thereby relying on the actual power ant. fuse under the dash to pop should an overload occur.
Once this was solved the motor was re-assembled and re-broken in for 10 minutes with 12v power applied to it.
Re-installed the motor to the ant. box and again tested it using power to make sure there was no binding or need of lube to make the antenna work.
Re-seal the box , install in car and now I have my factory power ant. working again for $0.00 since I had lube and emery cloth here on my bench.
After the first week of use the ant now goes up all the way and retracts properly as well.