Radio Wiring and Amp Bypass

[brbahner]

Hey so i know you audio gurus will think this is a ridiculous question, but fuse 23 has been blowing on me and im assuming its because of my aftermarket head unit and the way its wired. i would like to pull it and use a delete panel while i try and figure out what to do about audio in the near future. So my question is, do i just cap all the wires when i get behind the unit? or is there a specific way to delete a head unit and connect the wires while keeping their integrity for a later date. i have premium sound if thats of any help.

[325Eblue]

Alright yes I do have a spare amp so I wanted to keep the plug intact but the thought was just to leave everything intact and just plug in a new better amp same location same wiring set up just different amp thought instead of hacking into the rear harness bundle just plug in the adapter and use the desolder leads to go into the new amp not changing anything but the amp thanks again for getting back to me I may be inheriting a 528i wagon touring lots of room for some killer new audio gear that you have seemed to perfected for beemers thanks brutha!

[StereoInstaller1]

Alright so I made it thru 15 pages of this monster 30 page thread pretty sure I got a handle on what needs to get done. I however what some advice before going any further , he he the reward is a super clean pic of the inside of a 27 year old stock amp blaupunkt I think these are and it looks like it should be working? idnk , there are no burn marks,no swollen capacitors, nothing melted etc just gave up I guess? SO thanks to a super kewl RV3 dude I have another stock amp coming in the mail and that should be a good temporary band aid while I sort out the next step, just couldnt go without music on the morning drive anymore and I really dont wnat to hear the brake limiter noises telling me to work on that gees whats more important here LOL

the ride is a 1987 325 is she has the front tweeter pods, has a working fader, had a working trunk amp, the PO installed a JVC head unit the rear speakers are orginal the rectangle shape with the raised angled seperated horn. Okay so the JVC head unit was playing clean and loudly with the stock premium system, working fader amp etc. The amp has died I am pretty sure the front tweeter pods were still working because the music was pretty loud, umm cant remember what is in the kick panel under the front dash, hope I am not missing anything for a good diagnosis Paging DR. Luke

So it seems like with an aftermarket head unit already installed, speaker sound good, fader working, and most everything at hand in good shape I have an easier task but here is my question... sorry in advance for this thread clogging size post

looking at the back of the stock amp you can see a group of 4 wires together then a single solo wire , then a group of three wires.... after that it repeats the same grouping in reverse so then a group of 3 wires , then a single solo wire, then a group of 4 wires so 8 per pattern X's 2 patterns 16 total.

Couldnt I find a way to just de-solder these leads and re-solder to a modern input plug to mate to a modern amp producing channels back in the loop to the stock harness and speakers?

I would be upgrading the amp but keeping the circuit in the same closed loop pattern?

Thanks much :grin: S

So, I don't understand why you would care if that stock amp plug gets cut off or not, seems a damn silly thing to worry about, especially since someone hacked the front to put a JVC in.

You could unsolder the plug and solder wires on...or just crimp little pins on those same wires and plug each one in. I guess if you have a spare amp lying around, but sure seems like a buttload of hassle for nothing.

Oh BTW: using speaker level signal for an amplifier input is pure hack when you have an aftermarket deck and an aftermarket amp. Get off your ass and run some fucking RCAs. (exception: if you own one of those Alpine KTP445, use high level because you bought a shitball amplifier) Use that stock harness (seriously, why would you care if it's hacked? Resale?) for speaker wires, but to use it with an aftermarket deck as an amp input is just horrid. (again, unless you bought that turd of an Alpine)

As far as that stock plug pinout sequence, its not that complex. You have 4 positive inputs, 2 negative signal grounds (chassis ground on all BMWs BTW) 4 pairs of speaker wires, power, ground and remote. It's nothing unusual, just 4 pairs of speaker wires with inputs and power, like any other little POS stock amp in pretty much any car so equipped.

[325Eblue]

Alright so I made it thru 15 pages of this monster 30 page thread pretty sure I got a handle on what needs to get done. I however what some advice before going any further , he he the reward is a super clean pic of the inside of a 27 year old stock amp blaupunkt I think these are and it looks like it should be working? idnk , there are no burn marks,no swollen capacitors, nothing melted etc just gave up I guess? SO thanks to a super kewl RV3 dude I have another stock amp coming in the mail and that should be a good temporary band aid while I sort out the next step, just couldnt go without music on the morning drive anymore and I really dont wnat to hear the brake limiter noises telling me to work on that gees whats more important here LOL

the ride is a 1987 325 is she has the front tweeter pods, has a working fader, had a working trunk amp, the PO installed a JVC head unit the rear speakers are orginal the rectangle shape with the raised angled seperated horn. Okay so the JVC head unit was playing clean and loudly with the stock premium system, working fader amp etc. The amp has died I am pretty sure the front tweeter pods were still working because the music was pretty loud, umm cant remember what is in the kick panel under the front dash, hope I am not missing anything for a good diagnosis Paging DR. Luke

So it seems like with an aftermarket head unit already installed, speaker sound good, fader working, and most everything at hand in good shape I have an easier task but here is my question... sorry in advance for this thread clogging size post

looking at the back of the stock amp you can see a group of 4 wires together then a single solo wire , then a group of three wires.... after that it repeats the same grouping in reverse so then a group of 3 wires , then a single solo wire, then a group of 4 wires so 8 per pattern X's 2 patterns 16 total.

Couldnt I find a way to just de-solder these leads and re-solder to a modern input plug to mate to a modern amp producing channels back in the loop to the stock harness and speakers?

I would be upgrading the amp but keeping the circuit in the same closed loop pattern?

Thanks much :grin: S

[Bullhead]

Hey Luke I have an 87 just has 4 speakers and no fader. I only see 2 sets of speaker wires and when I test them they just power the fronts. I looked behind the antenna and all I found was the lighting box so I don't think I have an amp either. Are the speaker wires for the back and front under the rear seat? And should I just run some monster wire to the rears, I would like to use the stock setup but I am confused.

[Bullhead]

This may have been said , but do you use the crimp splices or do you actually cut into the dash wires to connect to the aftermarket deck? Or does it not matter?

[Excellent30]

Hello everyone, I have a 1988 325i Convertible with tweeters and a stock amp in the back. After installing a new head unit, the sound does not work past a certain (medium) volume due to the amp. I purchased a cheap 4 channel amp to replace the stock one instead of running new wires all around. When I cut the amp harness in the back, I noticed that there was only 16 wires. I do not know which ones belong to which speaker because this assortment of colors does not match any guides I have read. They are:

One that's all white (power?)
One that's all brown (ground?)
Black/White
3x Black/Brown
Grey/White
Grey/Brown
Red/Grey
Red/White
Yellow/Red
Yellow/Black
Blue/Black
Blue/Brown
Violet/Grey
Violet/Black

Any help is highly appreciated, I have been trying to figure this out for a while.
Thank you

[StereoInstaller1]

Yes, exactly. It's best if you test from the trunk, but you would need to unplug the deck.

[Musij]

Thanks for this Luke. Everything was super easy once you peel back the tape and see the twisted positives and negatives. First time playing with car wires and I installed a new HU and did the bypass in less than an hour. Everything works and sounds great except I get no sound from the front left speaker. I took the kick panel off to see if there was anything disconnected and it looks fine. I double checked my wiring and that looked fine. Should I battery check if my speaker even works? This is a 91 325i premium sound with all 8 speaker wires present in the amp. I did not have to run a single new wire

[15Michaeljoseph]

I have a 1987 325is with premium sound. The problem I have isusing the following diagram my stereo only gets power when I turn on the parking/headlights.

Car Deck
Red/Green (fuse 21) Yellow (constant power)
Violet/Grey (fuse 12) Red (switched power)
Brown or BR/BK Black (Ground)
Grey/Red (from light switch) Orange (dimmer)
White (yes there are 2)Blue (antenna remote)
White (still 2) Blue/white (amp remote)

theres a white and yellow pair of wires that come out the back of the HU, and they say 'battery' on them. I'm trying to reinstall my 87 325is's unit, but I can't find any other white or yellow wires to connect these to.... what do they hook up to?


--Mike

[agent]

It may just be the speaker - that was the case with one of mine. Swap the rears and see if the issue follows the speakers or the connections.

[madbim]

I did this tonight, and the right rear speaker only has sound coming out of the tweeter? Does this mean I goofed somewhere in the wiring or is the speaker blown?

[StereoInstaller1]

I'm trying to follow Spyke's method but am unsure about what to do with the Solid yellow and Solid blue wires in the picture below. Does anyone have any insight? My wires match his perfectly otherwise.

It depends on which car and which system you have.

Generally, if you see solid blue and solid yellow, you need to unwrap the harness between the deck and the fader...keep going!

[e30Prestige]

I'm trying to follow Spyke's method but am unsure about what to do with the Solid yellow and Solid blue wires in the picture below. Does anyone have any insight? My wires match his perfectly otherwise.

[StereoInstaller1]

Sorry I am late on this. Just to confirm, I only had one main ground and that was solid brown. All my speakers had (+) and (-) leads, which were kept individual all the way through the e36 adapter end and the Metra harness.

NOWHERE did I say to join or splice multiple wires together, as Luke mentioned it's a big no-no. Every wire front & rear has it's match. If you're doing it my way, do it just as stated or shown in photos, and you'll be happy. Do not confuse front speaker wires with rear speaker wires.

And test lights people, test lights.

*like*