Brian Bowman

I've just upgraded my stereo in my '80 Euro S from the original Blaupunkt Heidelberg (cassette) to a Blaupunkt Tokyo. While I was messing around in the center console, I found a red wire that was not connected to anything, but coming from the same bundle of wires as the stereo wiring. As the Heidelberg only had connections for +12v, Ground, Ignition, and power antenna, I'm wondering if perhaps this could be the "illumination" signal?? (i.e. triggers the radio's dimmer when lights are turned on). Haven't done anything with it yet... any ideas? The wire is red, but then so were both the +12v and ignition 12v wires...

-Brian

Randy V

I'd guess that it is for the antenna amplifier.

jforde

I am also replacing my radio. I have an 82 928 with a Blaupunkt Bamberg. I am replacing it with a Blaupunkt Honolulu. I had Red switched and Brown ground heavy gage wires. And a red non switched and white antenna lighter gage wires. The light gage red is the clock/memory always on power. On mine it has an inline fuse.

I am now working on the trim. The radio doesn't fit with the stock console trim, and I may need to do someting with the warning module. I am not sure yet. I may try removing the bezel from the Honolulu and see if I can retain the stock trim. i want to avoid any cutting if I can. Good Luck

-Jim

Brian Bowman

Thanks, Randy - I'm betting you're right and this is power for the antenna amp. This red wire was in ADDITION to the to red wires mentioned above for unswitched and ignition switched 12v. Still haven't tested it, but Randy's guess makes the most sense so far.
-Brian

Randy V

Here's an antenna function test and wiring guide I had archived from a Rennlist post by Wally:

First thing to do is to check and make certain that your antenna amplifier
is hooked up and functional.
1) Get to the back of your radio and find the antenna lead-in. Attached to
the lead-in should be a small black wire. This is the power supply wire for
your antenna amp. It should be hooked to a switched 12 vdc source, such as
the "power antenna relay" terminal on the radio. Note that the same 12 vdc
source is needed to trigger an out-board audio amplifier.
2) If the black wire is not hooked to a suitable 12 vdc source, hook it up.
Performance should improve.
3) If the black wire is already hooked to a suitable 12 vdc source, make
sure that you really have 12 vdc.
4) If you the black wire is hooked to a good switched 12 vdc source, turn
the radio on and tune to an AM station. Unhook the black wire - AM
reception should get noticeably worse. Hook it back up - the reception
should improve. If it does so, the problem isn't your antenna amp. If there
is no change when you unhook/rehook the amp, the amp is probably bad and
should be replaced.