Power antenna switch wiring

My guess is someone wanted the antenna to be controlled by the stereo "antenna" signal. As to why it does not work, you will have to figure out the rest of the wiring.

 

For the more modern type of automatic aerial motor as Mitchell said -- that mod is connecting one of the BR (white/red) aerial motor wires always to +12V (the H grey wire). Of course, what's going on at the other side of the aerial motor (or what brand aerial motor) is unknown.

If your old harness was unmodified (and the stock manual aerial worked) just reconnect the BR wires to where they were.

But why does a "new" harness have a modification? Or was/is it a used harness just new to you?

 

I found a similar mod on my 328 where the radio had been changed and an automatic aerial installed so that latter was activated and deactivated by the radio when it was switched on.. As far as I recall, 12v was constantly applied to one of the aerial feeds and the other was redirected to the radio aerial connector which applied 12V when the radio was on. It was simple to reverse but then the automatic aerial no longer worked. There is a way of modifying an automatic aerial with a diode to make it work like a semi-automatic and I used this until I could replace the aerial with a semi-automatic like this:

MQ-1 AM/FM Semi Automatic Car Power Antenna | eBay

GG

 

If you want to move back to stock configuration, you need to have 2 wires into the switch and 2 wires out from the switch. 12V & Grd in, and ant 1 & ant 2 out, and it actually does not matter the polarity. The switch simply applies voltage in one direction and reverses voltage in the other direction. In fact the two wires to the antenna have the same red/white colors.

 

I recently redid the center console on my 1978 GTS. My car does not have a radio at this time but it did have a functionally equivalent OEM antenna switch and an aftermarket powered radio antenna. I was determined to ensure that the wiring was compatible with any radio or powered antenna I might install in the future.

OEM wiring for the powered antenna consists of a power lead to the antenna switch and 2-wires (white with red tracers) going to the OEM powered antenna. The OEM antenna switch is spring loaded in the center position. Push forward and the antenna goes in one direction. Pull backward and it goes in the opposite direction, just like a powered window. Polarity is not changed at the switch. The switch merely sends +12VDC to one lead of the antenna causing it to run in one direction or to the other antenna lead which causes it to run in the opposite direction. With the switch in the center position, neither lead to the antenna is energized. The antenna is grounded to the chassis.

The replacement antenna, has a built in relay that works a little differently. Again, there are 2-wires from the antenna switch to the antenna. I used the same OEM white with red tracer wires but with slightly different function. One white wire with red tracer provides +12VDC to a white wire on the replacement antenna. This wire is hot all the time. The second white with red tracer wire is a signal wire to the antenna and is connected to a blue wire on the antenna. When energized by the switch, now a simple on-off switch, the antenna rises until fully extended, then shuts off automatically. When the signal wire is switched off, the antenna fully retracts and again shuts off automatically.

For automatic operation of a replacement powered antenna by a radio, +12VDC is supplied to one of the liberated white with red tracer wires in the console connected to a white wire on the antenna. The second liberated white wire with red tracer is extended to the radio antenna terminal and the other end is connected to the antenna blue wire. Now the antenna will extend when the radio is switched on and retracted when the radio is switched off. One can now repurpose the unused switch (position).

I hope this helps.

Bill

 

One wire in (12V to centre contact) and two out (each end, one up, one down)