‘75 Eldorado automatic antennae

[benji808]

My understanding is that when the radio is turned on, the antennae should automatically raise 12", with the option of extending further using the switch, then automatically lower when the radio is turned off.

On my car, it appears that someone wired a secondary (?) power source from the switch, so the switch works, but nothing automatic. The pink wire from the radio (which based on diagrams appears to be the trigger to the antennae) appears to be correct and intact, and the original 4-plug that goes into the antennae motor is also there, but when I plug it in nothing happens.

So...does anyone have experience with what wires are supposed to do what and how to troubleshoot?

Any thoughts appreciated.

Thanks!

[cadillactim]

When the radio is turned on the relay energizes and power goes through the green wire to the antenna. In the DOWN position power from the green wire goes to the black wire on the one limit switch. When the antenna raises about 12 inches that limit switch opens that circuit and the antenna stops.

When that limit opens the green to black wire circuit it closes the green to red wire circuit. Now power is at the dash switch, and that switch can raise or lower the switch.

There is another limit switch that stops the antenna when it is all the way up or all the way down.

When the radio is turned off power goes to the white wire from relay which lowers the antenna until the limit switch stops the motor.

The other limit switch then opens the red to green circuit and again closes the black to green circuit.

This limit switch is common to go bad. When it does the antenna will not respond to the dash switch.

Tim

Tim

[benji808]

When the radio is turned on the relay energizes and power goes through the green wire to the antenna. In the DOWN position power from the green wire goes to the black wire on the one limit switch. When the antenna raises about 12 inches that limit switch opens that circuit and the antenna stops.

When that limit opens the green to black wire circuit it closes the green to red wire circuit. Now power is at the dash switch, and that switch can raise or lower the switch.

There is another limit switch that stops the antenna when it is all the way up or all the way down.

When the radio is turned off power goes to the white wire from relay which lowers the antenna until the limit switch stops the motor.

The other limit switch then opens the red to green circuit and again closes the black to green circuit.

This limit switch is common to go bad. When it does the antenna will not respond to the dash switch.

Tim

Tim

Ok- that is helpful. I have power to the green wire at the antennae, but nowhere else.

Where is the limit switch and what does it look like?

[cadillactim]

Both limit switches are in the metal housing of the antenna. 

Tim

[benji808]

Can one buy new switches, or do you have to replace the whole housing and/or motor?

[V63]

For what it's worth, clocks are very sensitive to low voltage situations so if your car sits a lot and voltage drops ...it typically does not end well
For electric system. Best keep a tender on it. Also if you change a battery or connections be sure to make your last connection assertively and hold there while securing fastener.