Factory radio wiring

[mxl556]

I am putting two channel factory/dealer instaled Blaupunkt radio/cassette in my 81 320i. Factory wires including the fader switch are there, so it is easy to plug it all back in.However, speakers in my car are aftermarket 4ohm 35w units and I am concerned that they may damage the internal amplifier of a factory radio.

I have read that the factory speakers were 8 ohm but not sure if it only applied to 2 speaker systems in older Bmw's (2002's).

The question is- does anyone know if bmw's "common ground" wired speakers are wired in series or in parrallel? Anybody is using 4 ohm speakers with the factory radio?

My understanding is that if I have two 4 ohm speakers per channel wired in series, the amp will have the equivalent of one 8 ohm speaker per channel connected. I am hoping it is the case, but wanted to ask since I do not have the wiring diagram handy.

Thanks,
Max

[dreiermann]

I have 4-ohm speakers running through factory wiring (including dash-mounted fader), and a 1975 (approximately) Blaupunkt Frankfurt. It all works fine, but I had thought that 4 ohms was the same impedance as stock. At one point, I made a diagram of the speaker wiring (I had to re-connect the fader), but I can't find it immediately. If I can find it, I will post it.

[amarino]

Here is from the '81-'83 ETM

81-83-radio.png

[mxl556]

Thank you, I have the same radio (bavaria s) and glad to hear that 4 ohm speakers work fine. I checked Bmw etk and it hows both 4 and 8 ohm speakers.

The reason I am asking this is because while researching radios I found that older blaupunkts are supposed to have one 8 ohm speaker per channel but I suspect it only applies to 1 or 2 speaker systems. Perhaps my theory that e21's wired in series using four 4 ohm speakers with only 2 channels (8 ohm each because of 2 speakers on each channel).

Max

[OLD MAN]

Max a little of topic - can you get a picture of the radio mount?

Mine has been out of the car forever.. There is a steel bracket that holds the back of the radio correct?

Thanks

[mxl556]

Here is from the '81-'83 ETM

81-83-radio.png

That is very helpful, thank you!

- - - Updated - - -

Max a little of topic - can you get a picture of the radio mount?

Mine has been out of the car forever.. There is a steel bracket that holds the back of the radio correct?

Thanks

Daryl,

I do not have that bracket for the A/C console but I have to look in my spare parts, I may have it. I believe there supposed to be one as there is a stud on the back of the radio and 10mm bolt where the AC evaporator sits. However, it will not go anywhere without that bracket.

What exactly you are trying to figure out? What radio do you have, they mounted slightly differently depending on the radio model.

Max

[epmedia]

Here's a copy of the whole electric manual for the '81-83 320i.

http://www.findmymerchant.com/images..._1981-1983.pdf

[mxl556]

Thank you, that is very helpful!