Speaker wiring question

[pete9903]

(I know there's a sound forum, but not sure how many 80's-era BMW dudes browse there) I'm stuck trying to install my Pioneer stereo- Wired up the power/ground and unit turns on (but doesn't raise the power antenna, even though I connected that... will deal with that later). The head has eight speaker outputs (two each for R/L front, R/L rear). I decided to use the four output wires from the analog balance rheostat (basicaly skipping the rheo) and connect them to L front (+/-) and R front (+/-) outputs. No joy. I tried a couple other combinations, and nothing. Any insights? Thanks, and happy Friday beer o'clock.

[RSheiman]

There is a Post somewhere on what you did cause I followed it with no issues, assume you are following this. The system has a common ground for all speakers so I just combined all of these.

[GAflyer]

PM sent.

[CW6er]

(I know there's a sound forum, but not sure how many 80's-era BMW dudes browse there)

Our system is a bit strange, so you would probably have gotten a wrong answer anyway!

I'm stuck trying to install my Pioneer stereo- Wired up the power/ground and unit turns on (but doesn't raise the power antenna, even though I connected that... will deal with that later). The head has eight speaker outputs (two each for R/L front, R/L rear). I decided to use the four output wires from the analog balance rheostat (basicaly skipping the rheo) and connect them to L front (+/-) and R front (+/-) outputs. No joy.

The in-dash rheostat is a front/rear fadder, not a left/right balance.

I tried a couple other combinations, and nothing. Any insights? Thanks, and happy Friday beer o'clock.

Do you have your ETM yet?

Ok, you've got an '87, so you have the "premium" system with the separate Amp in the trunk. It is located in the trunk on the right side behind the access panel and it will accept speaker level inputs from a radio head unit (HU). As mentioned, the speakers only have a single wire between the head unit and the Amp, but the speakers are not common ground, it is the head unit ground and the Amp ground that are common to the chassis, not the speakers themselves, so you DO NOT twist all of the speaker ground wires together! You just connect the positive wire and tape up the ground for each speaker output, don't twist them together, and don't connect them to anything. I know it sounds like it can't work but it does, the Amp is not like most aftermarket amps, it is designed to do this. The output from the amp to each of the speakers have the expected two wires, +/-, it is just between the head unit and the amp that a single wire is used. See the ETM.

Here is a link to the explanation of how to hook it up with the wiring diagram for the car and the Amp to the speakers. My post also contains a link showing the which wire colors to connect to hook up a new head unit, so follow it also:

http://bigcoupe.com/phpBB2/viewtopic.php?t=12962&

If you hook it up right and is still does not work, there is a separate fuse at the Amp in the trunk (it may be an external inline fuse). There is also a separate fuse at the original radio head unit. It is shown as an internal fuse, but it may be an external inline fuse also, so check for that also. Check fuses 12 (HU), 28 (Amp), 21 (mem) in the fuse box. The Amp uses the same power source in the trunk (fuse 28) as the antenna, and it is turned on with the came signal that raises the antenna (WT wire), see the ETM.

Was the original radio working when you took it out?

[bkats]

In the 6er's, the 12v wire that powers the antenna ALSO supplies the amp. That's why the factory tape player raises the antenna even in tape mode. If you use a "power antenna out" on a newer head unit, the amp won't get power unless the HU is in tuner mode AND the "power antenna out" puts out 12v. Consequently, if you want to use the factory amp (i.e. not bypass it or use an aftermarket amp), you should run the "amp out" wire that's on your head unit to the "power antenna" wire on your car. This way, the HU will power the amp anytime it is on. This means your antenna will go up even if you're not using the radio, but w/e.

Not sure if this is your issue, but it is a rather important distinction to make, regardless.

[pete9903]

Thanks CW6er, really appreciate the in-depth reply. I haven't had time to sit down and follow step-by-step yet, but you give me hope that this will all work. Tough to justify much car time when my wedding is a month away.. more to follow, probably in July.

- - - Updated - - -

- - - Updated - - -

In the 6er's, the 12v wire that powers the antenna ALSO supplies the amp. That's why the factory tape player raises the antenna even in tape mode. If you use a "power antenna out" on a newer head unit, the amp won't get power unless the HU is in tuner mode AND the "power antenna out" puts out 12v. Consequently, if you want to use the factory amp (i.e. not bypass it or use an aftermarket amp), you should run the "amp out" wire that's on your head unit to the "power antenna" wire on your car. This way, the HU will power the amp anytime it is on. This means your antenna will go up even if you're not using the radio, but w/e.

Not sure if this is your issue, but it is a rather important distinction to make, regardless.

Thanks, I'll double-check this too.

Where in CA are you?

[bkats]

Where in CA are you?

Currently, in La Jolla. Moving to Carlsbad soon.

[oldcrow]

In the 6er's, the 12v wire that powers the antenna ALSO supplies the amp. That's why the factory tape player raises the antenna even in tape mode. If you use a "power antenna out" on a newer head unit, the amp won't get power unless the HU is in tuner mode AND the "power antenna out" puts out 12v. Consequently, if you want to use the factory amp (i.e. not bypass it or use an aftermarket amp), you should run the "amp out" wire that's on your head unit to the "power antenna" wire on your car. This way, the HU will power the amp anytime it is on. This means your antenna will go up even if you're not using the radio, but w/e.

Not sure if this is your issue, but it is a rather important distinction to make, regardless.

Joined the forum to revive an old thread and say...Helped my in-law install a new HU in his 99 M Roadster - had power but no sound - this was the issue.

THANK YOU

[bkats]

Yeah, it's one of those odd quirks that is hard to figure without an ETM. You're hooking up everything going "amp to amp, antenna to antenna. WTF?"

[midyear]

I have an 89 and don't have a factory separate fader control. I tried to follow the instructions above but have some differences in factory wiring.
HU turns on, memory works, but faded to full rear all the speakers play, faded to full front, none of them play...any help? I would love to post a picture of what I have going on but as a newby to the board, I don't see an attach option...thx all.

[1986series6]

I tried many of the solutions mentioned and none worked for me. Out of frustration, I eliminated the factory set up completely and wired the HU with + & - wires to the speakers.

No factory fader or amp. Switched the wire for the antenna so I could raise or lower at will. Never looked back.