1986 325es Aftermarket HU install

[rscott]

I bought this receiver for my car, a 1986 BMW 325es. I bought it without a stereo. I have tweeters in the door and what appears to be an amp in the trunk but it's in a really awkward place behind a bunch of brackets and I can't really see it.


http://i.imgur.com/XY5PrAS.jpg (click for huge)
This is what I'm working with, no idea how hacked up it is from the stock harness. Plug on the receiver is just a standard 16 pin Alpine.

Crutchfield says if I use this I can tap into the stock harness, for the speakers at least, but that appears to only connect two speakers, so would I buy two of those for the front and the rears? The big gray cable I know is for the antenna, and the white wire wrapped up with it raises up the antenna or something but I have no idea what everything else is supposed to plug into.

I've never installed a car stereo in my life before so I have no clue what I'm doing. What's the best way to proceed?

[fastnfurious7]

Pull your speakers & see what color wires are hooked to them. Follow them back to stereo hole. I do not believe they are in your picture. Use a voltmeter & do continuity test to make sure they're the right ones once you trace them back. Test 12v constant & 12v switched power with meter or test light. In your pic I believe purple is 12v switched, yellow is 12v constant. Brown is ground

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[rscott]

This is what the ETM has for my model year:




From what I can tell it looks like the stock harness is there in its entirety.

OK, from what I can tell by looking at this is if I get rid of the fader switch I should have four sets of wires that I can use for the speakers, I get my switched power from the purple/gray pair with the black plug on it. The white cable around the gray antenna cable goes to the antenna control. The only thing I can't find is the memory power wire and the headlight dimmer switch. Are those further back in the dash somewhere?

[rscott]

I stripped the harness back pretty far and this is what I ended up with.




The only problem I'm seeing so far is that I've only got 4 speaker wires and I need a positive and a negative for FL/FR/RL/RR. Everything else I think I can figure out with the ETM images.

[fastnfurious7]

Red/Green is the always hot/memory wire. I think the negatives for the speakers use same ground in the stock configuration on the rear.

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[fastnfurious7]

FR- = Grey/br FR+ = Grey/wht
FL- = Grey/voilet FL+ = Grey/red
Diagram positioning is odd here as the labeled right hand speaker is on the left side of the diagram for the front...the rear is proper.
RR & RL- = blk/brn RL+ = blk/violet & RR+ = blk/wht
That's according to the diagram. A continuity test will confirm.

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[rscott]

ok but those wires come out of the amp which is in the back of the car and my deck is in the front of the car. I need to figure out how to make the yellow/black, yellow/red, blue/black and blue/red wires split into eight. From what I've read these cars aren't common ground and if I have to rewire wire the fucking thing I'm just going to buy an OEM deck and return this aftermarket one.

[fastnfurious7]

To be honest, wiring straight to the speakers is the easiest thing to do. I didn't use any stock speaker wires. I wired external amps for everything & ran new speaker wire from the amps to each speaker.

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[rscott]

Could I do something with an external amp like using the 4 wires I've got running from the stock harness as RCA lines to an external amp and then use the stock wiring to the speakers back at the amp as normal?

If that's the case, recommendations on a 4 channel amp that will run the stock speakers?

[fastnfurious7]

You can definitely make that work with a speaker to RCA adapter or, some of the amps have provisions to directly hook up using speaker signal rather than RCA outputs from the HU. Again, personally I wouldn't do it that way. I'd run the RCA output from the stereo to the amp. It's really quite easy. I ran mine right down the center. The rear seat pops right out...run it under there & if you remove the back (only 2 10mm screws) there are existing holes to get the RCA's to the trunk. After that, you will need to route the remote amp turn on wire (usually blue off the HU) the same way. Then, run a 4 or 8 gauge fused positive from the battery to the amp positive (amp instructions will dictate what to use). Use same gauge as power wire to ground the amp. Then, you can hook the existing speaker wires to the amp. Mind the gain on the amp bc you will more than likely destroy the crappy stock speakers if you set it like you are supposed to. I like the Rockford Fosgate PBR300x4 bc it's reasonably priced, has decent power, & it's tiny.

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[rscott]

Color wire diagram for anyone needing it for an early E30 with premium sound.

[rscott]

Well it took me 4 hours, I accidentally cut the plug to the OBC controller so I gotta fix that, but the stereo works at least. God what a shitty job. One of the wires for the left rear speaker was a different color than the ETM diagram which threw me for a loop for a while. Mostly just awkward trying to solder/splice the harness together in the trunk when you're 6'4".

e: oh and fuck those BMW trim clips on the sill plate until the end of time. Why couldn't they just screw it down like every sane manufacturer?

[fastnfurious7]

Well it took me 4 hours, I accidentally cut the plug to the OBC controller so I gotta fix that, but the stereo works at least. God what a shitty job. One of the wires for the left rear speaker was a different color than the ETM diagram which threw me for a loop for a while. Mostly just awkward trying to solder/splice the harness together in the trunk when you're 6'4".

e: oh and fuck those BMW trim clips on the sill plate until the end of time. Why couldn't they just screw it down like every sane manufacturer?

Yeah...not a sane manufacturer. Lol! Mine are fubared & I gotta get new ones. Ha! Maybe that's why they did them that way...make you buy more. Glad you got the radio fixed up.