E34 stereo, 2 factory antenna wires behind radio?

[emotorwerks]

I am near the end of my installation of a new audio system in my E34 (more on that in another thread later) and I have a question about antennas.

Antenna #1
My E34 has what seems to be an aftermarket replacement power antenna. There are 2 wires, one power and one up/down signal spliced into the factory harness behind the radio that run all the way to the trunk on the right side of the car. Under the back seat I also noticed a strange antenna wire extension cable in the mix. All of this goes to a power antenna unit in the stock position. It uses the stock mounts and drain tube so it looks stock, but I can't figure out why it has a new set of power wires running up to the head unit. I also couldn't find a set of factory power antenna wires hanging around back there. Certainly the factory would not have done such a crappy job. The antenna wire for this one has the standard USA antenna connector for the radio and is a black cable.

Antenna #2
Behind the head unit is a second antenna wire running along side the cd changer wiring on the left side of the car. This one is gray and has a USA antenna connector on it. I traced the wire all the way to the rear deck and it disappears into the B pillar. I looked at the traces on the rear window and noticed they are broken up into a few groups. Could this be wired to some of these traces in the glass?

Here's the thing. I tested both antennas in the new radio and the gray one (#2) has much better AM and FM reception. I am confused by this and wondering if anyone else's car has this 2 antenna setup. FWIW, The stock BMW radio was hooked to the black power antenna wire and had crappy reception.

For now i'm leaving the gray one plugged in and I may leave the power antenna in the down position permanently.

Thanks a lot,

[BMWCCA1]

IIRC, your car didn't come with a mast antenna but used the top three-or-so lines of the rear-window defroster as AM and the lower lines as FM, or vice-verse. Due to many complaints of poor reception on the early cars, some resorted to installing a mast antenna, drilling a hole, etc. Later cars added some vertical lines in the defroster grid to increase the reception and then a wire in the front windshield for the dual-diversity antenna head-units.

[emotorwerks]

Hmm, very interesting. I did wonder if the mast antenna was an addon, but then seeing the factory mounting and drain tube I thought it was too good to be an addon. Well after a few days of using the rear window antenna, I am satisfied. I think i'll leave the mast antenna down and unplugged.

Thanks a lot for the info,