# 3 Questions About E39 Stereo



## mimic (Jan 9, 2006)

1) My FM has disappeared. I get no FM stations at all, just silence. Sometimes it comes back, but only for an hour at most then its out for weeks. AM / Tape / CD Changer works fine. Head unit keeps going to preset 7 when I switch to FM to see if its working. What could cause the failure of FM only?

2) If I remove my head unit to replace it with an aftermarket one, what features am I going to lose? I have a remote to unlock my doors and trunk and to lock / arm the car, CD changer, no DSP, arm by steering wheel that shows temp / avg. km's per L / approx. distance left in tank / avg. speed, and steering wheel controls. I can't think of anything else that might be controlled by the radio head unit. As far as I can tell, its just the basic head unit with a tape deck. From the 97/98 year of the 528 series.

3) Is there any way I can add another amp for a sub? The previous owner of the car obviously had another amp for a sub in there, the power and remote lines are left behind. I'm just not sure how to get signal to the other amp I want to add. It only has RCA inputs.

Thanks in advance!


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## mimic (Jan 9, 2006)

I've done some research and found that perhaps the antenna amp connections have come loose. This is apparently a known problem in early E39's like mine. Its apparently located in the "C pillar next to the rear glass". Just to clarify, is this the part of the interior between the rear windshield and the rear door?

Yes it is... now the question is... how do I remove it to gain access to the antenna connections?


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## mimic (Jan 9, 2006)

OK, so I pulled my C-Pillars off and found the AM and FM antenna amps. I double checked all connections on these amps and found no problems. FM kicked in for a short time, don't know if this was from me fiddling with the wires, but after about 15 minutes it died again, and did not return. Fiddling with the wires after it died did not bring it back again.

If anyone has any suggestions I would love to hear them. AM & CD's are only so entertaining. I miss FM!!


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## jvr826 (Apr 22, 2002)

1) Perhaps the fm antenna booster/amp is failing and needs to be replaced.

http://realoem.com/bmw/showparts.do?model=DD53&mospid=47585&btnr=65_0215&hg=65&fg=30

2) If you remove the MID you'll lose all of your onboard computer functions. But, removing the factory "head unit" could cause you other expense. The factory amp filters the frequencies to each speaker in the system, so removing it and retaining the factory speakers makes it difficult to get good sound. What most do is retain the head unit, bypass the factory amp, and get new component speakers with their own crossovers, and add a sub.

3) Yes, adding a sub isn't very difficult. Perhaps the previous owner had a Basslink. You can check the wires on the 26-pin connector, positions 1-4 and 14-17 to see if a tap connector was used on them. These are the pre-amp outputs from the NON-DSP head unit and I'd guess they used 14-17 since those are the rear speaker feeds.

If you want to know more about your system and how to upgrade it, visit my 1999 528i upgrade site. The pin-out on the 26-pin connector may not have the numbers correctly indicated, but positionally they are correct.


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## mimic (Jan 9, 2006)

You mean 1-4, cause those are the rear outputs... at least according to your chart. I've looked, the only thing they've tapped into is the 12V power line for the remote feed to the amp.

So essentially, if I tap into 1-4 with 2 pairs of wires and solder RCA connectors on the ends of the pairs and hook that up to my amp, it should work? I'll get signal?

And the answer is YES. I used pin-outs 1 thru 4 to get my pre-amp signal. Works great! Nice and bassy now. 

If only I could get my FM to work properly now.


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## el_duderino (Aug 1, 2005)

The outputs are not "RCA" preamp outputs. Whether or not you can run them directly into the amp depends on the amp (they are "balanced" signals and need a specific type of input or a converter such as a Peripheral SVEN or a Soundgate LOCB.2 or PREA. )

I would get them at the amp, NOT at the HU, and personally if you are adding just a sub I would not use the preamp outputs at all, but simply the rear woofer speaer wires into a speaker-level input such as many amps have.


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## mimic (Jan 9, 2006)

el_duderino said:


> The outputs are not "RCA" preamp outputs. Whether or not you can run them directly into the amp depends on the amp (they are "balanced" signals and need a specific type of input or a converter such as a Peripheral SVEN or a Soundgate LOCB.2 or PREA. )
> 
> I would get them at the amp, NOT at the HU, and personally if you are adding just a sub I would not use the preamp outputs at all, but simply the rear woofer speaer wires into a speaker-level input such as many amps have.


I never took it from the HU. I took the signal from before the amp. My sub amp does not have high-level inputs, only RCA inputs. I tapped into the 1-4 wires on the 26 pin connector, essentially the rear left and right pre-amp inputs. Its working great and sounds great.


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## el_duderino (Aug 1, 2005)

OK, but remember, before the amp IS from the HU. 

Sometimes doing that and retaining the OEM amp will cause engine whine in the OEM speakers, that's all.


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## mimic (Jan 9, 2006)

Thanks for the tip. So far I haven't noticed any engine noise. And what I mean by before the amp, is I spliced into the lines about 6 inches before the amp in the trunk. No where near the head unit or the engine.


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## el_duderino (Aug 1, 2005)

mimic said:


> No where near the head unit or the engine.


LOL... yeah, I knew that. Glad it works : )


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