I'm posting this as a 'sanity' check of my reasoning, and to hopefully avoid frying my electrical system and/or power antenna circuitry.

What I want to do is conveniently be able to have my power antenna 'up' all the time (in winter), or go up/down with the ignition switch (rest of the year).

On my power antenna, there is a wire for a constant 12V source (or one that is that is 'on' with ACC and/or IGN), a wire that is supposed to see 12V (radio 'trigger') only when the radio unit is turned 'on', and a ground wire.

My stereo head unit doesn't have an antenna 'turn on' lead, so assume I'm working with a switched (ignition in ACC or RUN position) 12V trigger. I always have the radio on, so this is no problem. I also go to brushless carwashes, so having the mast always up when running the car is fine. I want the antenna to go down except in winter, though, to protect from vandalism (vandals don't like cold air, right?), and I also want to be able to retract it at the flick of a switch even in winter mode (putting car on a hoist, for example).

What I'm thinking of is connecting a constant power source with a toggle switch to the 12V constant input wire of the antenna, and the trigger (radio turn-on) wire to a switched ACC source. As I understand it, the 12V source, not switched by the radio turning on/off, is for the purpose of applying power to the antenna motor after the radio is turned off, to lower the mast. I believe the power antenna has a circuit that checks the current draw of the motor to measure it's load, and when it exceeds a threshold, stops it. So, when the antenna is down, the constant voltage wire should not be connected to the motor and no power should be drawn from the battery.

For summer season use, the toggle switch will be on, allowing the antenna to go up/down with the ignition on/off. For winter use, the toggle switch will be 'off', so no power can get to the motor to retract the mast. If I need to retract it temporarily, I'll turn the toggle 'on', then 'off' to resume winter (always extended) mode.

Is this too simple to be correct, or is there a flaw in my reasoning here?

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1986 560SL
2002 Toyota Camry
1993 Lexus