power antenna

I have a 3 wire power antenna. It has a 12v constant (red), a ground (black) and a 12v trigger (green). To make it go up, it needs both 12v leads and ground. To make it go down, the trigger goes to zero. Under those circumstances, the antenna will only go all the way up or all the way down. I want the antenna to stop 1/2 way instead of full extension.

I have a 3 wire switch. I believe that I can run power to the common terminal, the "up" side of the switch to both red and green (and ground the antenna). I think that I need a diode between the "up" and "down" outside terminals of the switch....to isolate the green trigger.

Does that sound right? If so, what kind of diode am I looking for?

Thanks for the help.

The only way you can stop that antenna at half mast would be to break the power connecton when it gets to the point in which you want it to stop.

If your radio is equipped witha power antenna lead, you can connect it to the green wire of the antenna..  Place a switch on the red wire going to the antenna, when the antenna gets to the point, turn the switch off.

Or, break the ground connection.

Using the radio AND a swtich is not very creative...........I know it can be done the way I describe, I'm just not sure about diodes and which one to use. The OEM's did it that way for years.........but I just can't find anything on the 'net.

Thanks for the input!

Breaking the ground connection will probably not work.  There is a good chance that the chassis of the antenna is connected to the ground wire of the antenna motor.  If you break the ground connection, you would have to isolate the antenna from the car's chassis to have the motor stop.  Break the positive wire with the switch.

The diode thing was for antennas that were designed to run at half mast or all the way up.  Yours is an all or nothing device.  The antenna is limiting the creativity. 

hi,

use a 6A diode.  wire power in on the center/common terminal.  the up terminal gets the green lead and the non-banded end of the diode. the down terminal gets red lead and the banded end of the diode. ground the black lead.  you just turned a fully automatic antenna into a semi automatic one : )

m

Yep....figured it out today, bought the diode and it worked just like I want.

Thanks to everyone!