Your truck is the same as mine; 4.
The ONLY time I want or need the power antenna up is with terrestrial radio.
When I turned off the radio, the voltage went down to 0 took a second or two; not instant and then the antenna retracted.
It provides a very low signal to noise ratio and provides a signal gain of 20 decibels dB.
If you don't need it the wire from the stereo should be capped off to prevent a short occurring if it were to ground out under the dash somehow.