Question on 89 750 radio

[SergeBMW]

Im looking to install a new VDO Radio HU in the car, best looking radio I could find that looks and functions good for this car. I am seem to have found the speaker pinouts but am unsure of a couple of connectors. Ill post a photo below explaining which ones I am unsure of. Also, how does the new head unit work with the existing amplifier? My previous E32 had already come with an aftermarket Sony HU so when I upgraded to another Sony it was just plug n play. The car did have the same amp I have now on my current E32.
This is the unit I am looking to buy, any other ideas would be greatly appreciated, just want something that looks good with the dash that has some modern features.
https://www.ecstuning.com/b-vdo-part...d7416u-or~con/
980069_x800.jpg

My current BMW radio is a Pioneer KE83ZBM. Has multiple connections with different connectors.
Radio Connections Marks.jpg


For these, I have no idea what they are for or if they are just there for other features I dont have? The blue one seems to be part of the radio harness
Disconnected wires.jpg

[yukon101]

From the diagrams I have found since its not coded to be the modern pin out is the solid white and yellow wires are left front mid-range. As for that blue connector it appears that is for the speed volume control, as for that other connector I cant seem to find anywhere. The weird thing is I cant find the gray/black wire for the night illuminator or on the newer universal pin out orange is the illuminator. As for the amp I have no idea, usually so long as the wiring is correct with the grounds/positives and doesn't get reversed its good. At least that was with mine and when I changed the HU on my oldsmobile with the Bose system that "has to be redone."

[cirrusblau]

Please post pics after you install this. I'm interested how it blends in the E32's interior. Thanks

[august125]

I believe the black/white wire going into the 1-pin male blue connector is the speed signal for radios with speed sensitive volume control.

[SergeBMW]

Please post pics after you install this. I'm interested how it blends in the E32's interior. Thanks

Ive decided to wait until after Christmas to purchase it, saved that money to use on needed repairs to the car first. But yes, I will upload photos.

I believe the black/white wire going into the 1-pin male blue connector is the speed signal for radios with speed sensitive volume control.

Do you happen to know which radios had this feature? I think it has a place for it on the radio but it doesnt seem to stay in enough. Small little connector that reminds me of the radio antenna port on wifi PCB modules on computers.

[yukon101]

I think its the Alpine radios that use them, I picked one up from the junkyard and it worked correctly. For your system I do not know for sure.

[unity]

Alpine CDE-164BT is the head unit I installed into my E32. The color can be matched exactly to the interior orange but it is brighter. It was not until it got cold out that I noticed it shifts into the reds more until warmed up. Very odd since I would think its all LED illumination. As for the heat unit, I wanted bluetooth and it works perfectly. And I can take calls through the head unit as it comes with an external mic. Its like a modern car now and I love when a call comes in and the music fades out with number displayed on head unit. But the radio does not support speed volume adjustments like the factory one did. Really with how quiet the E32 is, I never felt it was needed. That and I really like to crank my tunes!

As for the amp.... the factory amp sucks, it will die. Mine died. And if you head unit has a pre-out (usually +4 volt I think?) then it will really kill it. I hate to say it, but pick up a CHEAP aftermarket amp. A four-channel can be made to work. I did it.

For connecting the head unit, I bought:

From head unit, Alpine only:
https://www.ebay.com/itm/172423141180

This connects to the factory radio connector and provides an antenna adapter:
https://www.ebay.com/itm/301510668348

With the above, I simply wired together as needed. Very simple. Only thing was the blue wire. I think the factory wire is solid blue and that connects to my head unit on the blue with white line, NOT the solid blue. This was also the case with teh previous installed Pioneer head unit. You will NOT want to shorten any wires! Leave them long so you can tuck the huge connector UP and to the LEFT inside the dash before installing head unit.

Now if you dont want to replace the amp, you can stick with above and call it a day. Easy work. If you want to replace the amp, its more work but not hard. In my case, I went with a 4-channel Alpine amp I have used since 2002 or so. I combined whit with a second amp for Subs. Originally I did not use RCAs with the Pioneer, but for the Alpine, I finally installed them. So subs are easy, they got the signal from the Sub RCAs off the head unit.

For the rest, a problem. ALL speakers wire back to the trunk....

IMG_3493.jpg

So thats 5 speakers per side to wire. What I ended up doing was to keep stereo but lose the front/rear fade ability. This way I could split the amp for highs/mids and then lows.

Channel 1 Front Left channel controls ALL left high/mids. (dash mid 2.5" speaker, front door high tweeter, rear mid 2.5" speaker)
Channel 2 Rear Left channel controls ALL lows (5.25" front kicker panel, 5.25" rear shelf)

Channel 3 Front Right channel controls ALL left high/mids. (dash mid 2.5" speaker, front door high tweeter, rear mid 2.5" speaker)
Channel 4Rear Right channel controls ALL lows (5.25" front kicker panel, 5.25" rear shelf)

So there is my four channels. The amp is then tuned with built-in crossovers and filter passes accordingly. They are paired, so channel 1/2 are setup for mid/highs and channel 3/4 are set for lows. This again means I can not fade front/back but its not an issues. If I do so, I am really just adjusting the balance between how loud the lows are compared to highs/mids. Which is still useful for fine-tuning.

IMG_0613.jpg

The amps themselves are located in the cocaine bay. That large void just behind the rear seat. Excellent spot to put amps but its wicked tight, large amps will not fit! In fact, I picked up 90 degree RCA elbows to install and take strain off the new cables I put in. Originally it was direct wire as seen above with the Pioneer. I had a whine issue using factory signal wires to the truck. All gone now with RCA cables.

IMG_0618.jpg

Speakers. So with the above setup I am still using original wires FROM amps to speakers. No issues. The speaker themselves I replace with cheap eBay ones. They all fit well and sound great. I am very happy with it this last couple weeks. Too bad I am probably selling the car. I pick up a Land Rover tomorrow.

The above is probably WAY more than you need but I like to post as much as I can for anyone else that comes across these threads and the factory sound system is a little bit of a pain. If you have questions, let me know.

[SergeBMW]

Unity thanks for that great post! Lots of great info. I've thought of going this route but it is a lot of work and tweaking to get just right.
Did you find the audio to sound much better with this setup than with the stock system?
I'm going to keep your post for future reference if I do decide to go this route. Great idea with hiding the amps in the "cocaine bay"! Any issues with amps overheating?

[unity]

Things did seem to sound better but my amp did not last long when it did work. So I can not really compare. But then add the fact that the speakers where old and on the way out too. So like anything, replacing some parts of an aging system will usually always give better results.

I dont seem to have overheating issues but I had considered doing two things. Buying some grille covers and then I would cut two holes in the floor mat on each back corner above the bay (approx 4"x4") and insert the grills flush. Then on one side installing a fan with thermostat that would blow air up to one of the grills. The other side would draw in cooler air. But I have not had overheating issues and the amp I have both have automatic thermal shutoff. I would guess living in a warmer climate there may be an issue. The amps themselves have provisions for small 1" fans but they are not installed from factory. I would say if you have an amp with internal fans, then it would probably need more venting for sure.

[august125]

Do you happen to know which radios had this feature? I think it has a place for it on the radio but it doesnt seem to stay in enough. Small little connector that reminds me of the radio antenna port on wifi PCB modules on computers.

The little RF connector on the radio is for the diversity antenna feature on later cars.