I'm in the process of installing a new Kenwood AM/FM/CD unit with four new speakers in my 81 240D. The original radio is a Becker Europa. The old analog AM/FM only unit. I've run all new cables for the speakers, bypassing the fader control completely. I will be running a cable directly from the battery to the stereo for 12V constant.

I'm wondering about the keyed 12V. Would the original radios power wire work as the keyed 12V to the new one? I assume so as the Becker only came on if the key was turned. So that means it's "keyed 12V right?"

Also I'm a bit confused about the situation with the antenna. My Hirschman is problematic and I want to replace it with a simple non powered antenna. At least for the time being. Until I can get around to doing something about the Hirschman. But I note that when I turned on the old Becker the antenna would extend some way and retract when I switched the key off. The antenna switch would also make it extend further and retract somewhat independently of the key. So does this mean that there are two power sources to the antenna? One thru the antenna switch and one directly from the radio itself?

Electronics is a dark art to me so any input is appreciated.

- Peter.

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2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S