kellydw

Hi Folks---I am a newbie and this is my first post.

Bought an after market power antenna -three wire-one black, one red and one blue. Want to hook it up to the original factory power antenna dash switch in my 1968 -442. There was a post sometime back that involved the use of two relays but I think it was for a two wire antenna. I wired the relays up as per wiring diagram but it didn't work. Is there different wiring for a three wire antenna????

Loaded68W34

The antenna you have gets positive to the red wire and negative to the black wire. The blue wire is the trigger. If you connect it to power, the antenna will go up, if you remove power from the blue wire the antenna will go down. As far as using an original switch, you have two options. If you find a switch that turns on and off like the courtesy light switch that will fit, you can simply use it to supply power to the blue wire and leave the red and black wires connected all the time as intended. If you use the original switch, you can use diodes or relays to power only the red wire when the "down" terminal has power (switch pressed down) and power the red and blue wires when the "up" terminal has power (switch pressed up). You cannot simply use your original switch to give power to the blue wire when pressing the switch up because as soon as you let go and the switch returns to center, the antenna will go back down.

kellydw

Thanks for the reply--The original factory switch has a center off position and spring loaded to the right or left for up and down. Would like to get it working so the antenna would go up or down only while you are holding the switch on--in other words it could go only partially up or down by the amount of time that you hold the switch on--if that is possible

Loaded68W34

Yes, that is possible. As I said you will need to use diodes or relays in conjunction with the original switch. The switch gets a positive wire in and then supplies positive to either terminal as you press it up or down. The easiest way I can think of is:

Connect the black wire on the antenna to ground/ negative. Connect the center terminal of the switch to positive. Connect the red wire of the antenna to the "down" terminal on the switch. Run a diode between the "up" terminal and the "down" terminal on the switch with the cathode on the "down" side and the anode on the "up" side. Finally, connect the blue wire from the antenna to the "up" terminal along with the anode of the diode.

If you do this correctly, pressing the switch "down" will give positive to the red wire on the antenna causing it to go down only as long as you are holding the switch. When you press the switch "up", the red wire will receive a positive signal through the diode and the blue wire will receive a positive signal causing the antenna to go up only as long as you are pressing the switch. The diode is necessary to prevent the red wire from back feeding the blue wire (causing the antenna to go up whether you press the switch up or down). When you release the switch and it centers, the antenna is not connected to positive at all so it will not move.

I hope this makes sense. BTW the cathode on a silicon diode (black cylinder) is the side with the silver stripe. The cathode on a germanium diode (clear cylinder) is the side with the black stripe.

kellydw

Thanks again for the info--Is there a certain type or size of diode that I should use.?? I already have the two relays but as I mentioned the wiring did not work as was shown.

Loaded68W34

Diodes will have a current rating. As long as it can handle the current running through the antenna, any Diode should work. If you wire it as I described above, you will not need any relays. Just be sure to connect the center terminal of the switch to a fused power source.

kellydw

Thanks again for the help. I will get a 10 amp diode and give it a try --will let you know how I made out.--Kelly442

Loaded68W34

10 amp should be more than enough. I would think the antenna (with a modern motor) will draw less than an amp.

kellydw

specs for antenna say maximum current 5 amps, but I guess that means that is the most it can handle

Loaded68W34

You are correct that 5 amps is the max draw. That will likely be at motor start-up or when the mast bottoms out at the top or bottom of its stroke. You might want to limit the fuse powering the antenna to a 3 or 5 amp fuse, as if there is a problem, the motor or wiring to the antenna can fail before the fuse blows. I think you will be more than safe with a 10 amp diode.

danktx

Do you already have the factory wiring from the switch to the power antenna? If so, I would make one change to the suggested wiring. Put the diode at the antenna end that way you don't have to change any thing under the dash.


Wiring a new automatic power antenna to work with factory switch-antennawiring.jpg

kellydw

No I don',t have the original factory wiring for the antenna--just bought the switch.. Thanks

Loaded68W34

You are correct, you can add the diode and connections in line anywhere along the wiring between the switch and antenna.

BackInTheGame

Dan - It looks like you tried to post a pic. It did not make it.

danktx

You are right about the pic. I posted about the this very thing back in 2018. If you do a search for "Wiring a new automatic power antenna to work with factory switch" you'll find it.

matt69olds

I put a power antenna on my 69 years ago. I had to fill in the factory antenna hole in the fender, then drill a mew one about 2 inches forward of the original location. Unless your very familiar with these cars, a d know what to look for, it’s hard to tell anything isn’t the way it’s suppose to be. The factory antenna hole positioned the mast and motor to close to the firewall, hence the need to move the mounting location.

Since your car had a factory antenna (its in the trunk correct?) how will the aftermarket antenna fit the quarter panel? Kinda curious how you did it. I didn’t think a aftermarket antenna would fit the original antenna trim/filler pieces.

kellydw

My car didn't hav e an original factory antenna. I plugged the whole in the front fender and relocated the antenna to the passenger side rear quarter panel. It is about half way down and there is lots of room for clearence.