Radio swap OEM to OEM

[Restoman]

So I picked up a used radio after the original one refused to accept the security code. I'm very happy that I have a radio that works now. The rear speaker hook up is confusing.

Old on top right, new bottom left.


This picture shows the original four places that the speakers plugged in. The skinny long black area. 8 connections. This is not on the new to me radio.


New radio back. I don't see where to hook up the rear speakers.
Yellow wire and white wire has plug missing and thats getting fixed here in a minute. The plug to the right is for the rear speakers. There is no where if can see that it plugs in.



Car info: does have tweeter pods. no fader on the dash. Hmm. This probably is not premium sound.

My logic tells me that the speakers must just tie the front and rear of each side together. I'm not going to hack up anything until I hear from on of you guys. I'll keep looking though to see what I can come up with.

P.S. 1) I thought I read somewhere that the speakers did not share a common ground. Maybe thats not true at the head unit and I have an OEM amp hidden.
2) Even though the radio has 8 connection points, there are only 4 wires that the harness plugs in for the speakers.

[dillera]

Hello: I'm going thru some similar issues- I'm trying to re-install the OEM radio after many decades of other head units and insanity.

From what I've learned, you do not have premium sound, and so no remote AMP. That is why you have all the speakers coming back to your head-end. The new HE you are trying to install is the exact one I have from EBAY also. It is setup for premium sound- it expects to go back to an amp, and so only has 2 outputs, L/R. THose are the little rounded blue and yellow cap like plugs.

I think you should buy a cheap amp, run the new radio to the amp, and hook the amp up to each of your individual speakers.

[dillera]

Wait looking again- you show Blue/Yellow from the rear- why aren't you hooking those up to the blue yellow from the new HE on the rounded caps?

Pull all the caps off the HE and look- it tells you exactly what are the plugs are. Maybe I can take a picture here.

[dillera]

Here:



Connect to L/R

[accident]

The radio you bought is for a non-premium system. Those systems had a fader in the console directly above the radio. The front and rear speakers ran as pairs through this fader, both fronts and both rears together so that the audio could be faded to the front or the rear. The premium system eliminated this and thus split the wires.

[dillera]

The radio you bought is for a non-premium system. Those systems had a fader in the console directly above the radio. The front and rear speakers ran as pairs through this fader, both fronts and both rears together so that the audio could be faded to the front or the rear. The premium system eliminated this and thus split the wires.

From everything I've read, the premium sound had the fader.

[Todd Black 88]

^ my car has the fader and premium sound.

[GAJ]

My 1990 iS has premium sound with the OP's old radio and does NOT have the dash fader. My 1985 318i doesn't have premium sound, has the OP's new radio and DOES have the dash fader.

[dillera]

My 1990 iS has premium sound with the OP's old radio and does NOT have the dash fader. My 1985 318i doesn't have premium sound, has the OP's new radio and DOES have the dash fader.

Makes sense- you can SEE the fader in the OP's OLD radio. The new one (CM5907) is like mine, has no fader built in, and uses the fader in the dash.

[Todd Black 88]

Nope.

That new one is the exact same as the one that came in my 92 e30 cab with premium sound and no fader.
There are multiple versions of each deck I believe. I had two decks like the last one, and one had four speaker plug points, and on had only two.

[StereoInstaller1]

Guys, this is simple: ALL E30 before 1990 came with a fader, has nothing to do with Premium Sound or not. 1990 was the first year of "slider" radios that had normal 4 channel outputs. and an onboard fader.

OP, your "old" deck is newer than your "New" deck, that is why it has only 2 outputs, it is intended to go to a fader to split between front and rear.

[Restoman]

Guys, this is simple: ALL E30 before 1990 came with a fader, has nothing to do with Premium Sound or not. 1990 was the first year of "slider" radios that had normal 4 channel outputs. and an onboard fader.

OP, your "old" deck is newer than your "New" deck, that is why it has only 2 outputs, it is intended to go to a fader to split between front and rear.

So....I need to add a fader? Even if I did, I'd have to rewire? I thought that a working radio would be the fix, haha. I don't care to fade. Can I just join the left wires together and then connect the right wires together?

[Restoman]

Wait looking again- you show Blue/Yellow from the rear- why aren't you hooking those up to the blue yellow from the new HE on the rounded caps?

Pull all the caps off the HE and look- it tells you exactly what are the plugs are. Maybe I can take a picture here.

The white and yellow wires have a home. I clipped the plug off the non-working HU to put on this working one. Pictures were taken before work was done. Also trying to figure out aux input on this stereo.

[StereoInstaller1]

All the fader does is turn a 2 channel radio into an input to a 4 channel amp. If you don't care about the functionality, just parallel the /reds and the /blacks, the amp won't care, nor will the deck, it will behave just fine. Don't mix the yellows and the blues though.

What are you doing for an AUX?

[Restoman]

All the fader does is turn a 2 channel radio into an input to a 4 channel amp. If you don't care about the functionality, just parallel the /reds and the /blacks, the amp won't care, nor will the deck, it will behave just fine. Don't mix the yellows and the blues though.

What are you doing for an AUX?

Well following the guide for adding an aux seems to only touch on the radio that's coming out. I took apart the new unit only to find different color wires. The only thing that really comes off the tape deck to the rest of the HU has brown, orange, and red. Now I will try and figure out which wires do what. From what I understood one is ground and the others are channels. So I only need to get the ground figured out and I should be good to go.