View Full Version : Wiring a deck and resetting OBC clock

06-07-2006, 08:15 PM
Just got my first BMW this week. I'm trying to wire up a deck and this is the first time I'm stumped. I've done quite a few in the past, so I'm not fully new. I have found the Gray-Purple to be the ACC, Brown is ground, and red-green constant. I wired up all three of these but can't get the deck to power on, I've tried three different head units pulled from cars that all had them working. I've checked to make sure there is actually power coming from the wires, as I've hooked up a bulb. The bulb turns on, but the decks do not. Can anyone give me a clue?

PS. How do I set the 6 button OBC clock and date? I've been reading about pressing the small button with a pen, but there is no button!

06-07-2006, 08:30 PM
The most solid way of doing this is by running some new wires yourself. The only wire you should use from the car's existing wiring is the ACC wire (to be used as the 'remote' wire for the new deck).

Use a freshly run power wire and run a new ground wire. I grounded to the firewall just behind / left of the glove box.

If you are having problems at that point, I'd buy a cheap multimeter (very valuable tool to have) to help you trouble shoot.

Good Luck!

06-07-2006, 10:08 PM
So you're saying run a new ground and constant, and just use the main 12v line from the existing wiring?

Any idea on how to set the clock?

06-07-2006, 10:30 PM
You got it.. in most cars the constant power should be thought of as 'memory power' and the switched + is where the radio draws the main current (and is connected to through the radio fuse).

However, in most modern aftermarket radios the constant power is the line where the current is drawn from, and the switched + simply tells the radio to turn on and off.

To set the clock, I believe you hold down the time / date buttons or something. After you hold something down, press the min / hour button and it will cycle. (Sorry for the vagueness).

06-08-2006, 02:50 PM
It's weird, the switched line and constant line both have power (ground is also working), but my deck won't power on through those wires (not to mention that I keep blowing the fuse for the interior light and key buzzer). The deck does run fine from the battery though, so I guess I'll run those wires when i have time. I've taken a few looks, where is the best place to run the power and ground from (i'm guessing they both go directly back to the battery, or ground can be anything attatched to the frame). But in either case, what is the best route?

King Luis
06-08-2006, 02:59 PM
this helped me a lot.

The official e30 Aftermarket Radio Install Write up!
If you have the premium system ( tweeter on doors, plate speakers on rear deck )

* Yellow wire from new head 12v+ goes to Red/grn in dash
* Red wire from head ign goes to purple/wht in dash
* Black wire goes to brown wire in dash plus two extra brn/blks that were attached to old head. There will be three wires total hooked to the black from new head.
* Blue/wht from new head goes to both white wires in dash. If you don't have a blue/wht on new head, use the blue.
* That will leave three wires:
* If your new head has a dimmer lead ( usually orange ) it will attach to the red/grn lead in dash. If the new head does not, TAPE THIS OFF. No sense blowing fuses now when you are so close to sound.
* White wire from new head goes to yellow wire in dash
* Grey wire on new head goes to blue wire in dash.
* Tape off ALL REMAINING WIRES FROM NEW HEAD, don't allow them to touch each other or any metal in the dash.
* This uses the factory fader, and factory amp, without messy rewiring.
* Anyone who tells you that the new radio has more watts than the old amp needs to look at what it takes to make 40x4 rms. It sure ain't gonna fit inside a deck, and it will need at least 10ga power wire, which new radios don't have.
* I worked the install bay many many years. I did every e30 like this, and my 88 535is has had this wiring for 6 years, no problems. There is a common thread on these boards that says 'rewire' when it is not needed.
* If you have the std system without an amp, it is just as easy, there are two extra wires. Email me for details if so.
* If you are confused, take it to a reputable shop ( no Best or Circuit in the name ). 40 bucks and you will be in and out in 10-15 minutes.

its 12am here and I'm tired and bored. The proper illumination wire found in the dash of e30's is Red/GREY not Red/grn as I said. So shoot me, lol.

06-08-2006, 03:39 PM
A good write up, but I disagree with the principle of it. The factory 4x40 amp really sucks compared to modern in-dash players, and it limits your options later on. Also, the wiring in the e30 is very thin. The combo of the thin power and thin ground will also introduce limits.

Just buy a super cheap amp install kit (like $10 from xscargo), run the power from the battery (its not as hard as you think, just remove the rear seat and the kick panels on one side of the car).

Ground options are limited, but I found a nice one at the rear of the glove box, as I stated earlier. Do NOT run a wire back to the battery for ground.

Its likely that your radio is drawing more power than the factory wiring can provide.

Good luck.

06-08-2006, 03:41 PM
Best way to wire up a deck is with a test light or multimeter, and patience. Tape + sharpie marker to label the wires, and you're set for life.

06-08-2006, 03:43 PM
It should be noted that in my OWN install, I used the factory power with a new ground and used an aftermarket 4 channel radio. I only needed to splice two wires in the dash and run a new ground. I then spliced into the speaker wiring after the factory amp and disconnected it. I bought a cheap 4 channel amp from canadian tire for $160 on sale (some sony thing) and used the factory speakers.

The reason I didn't run a power for the deck is because I didn't use its on board amp.

Add in another amp for subs and a couple 10s or 12s and you can get a seriously good sounding system on a total budget.

Ask Chromius_e30 what he thought of the sound.. I like it.

06-08-2006, 03:52 PM
Thanks, that worked!

I'm using a really crappy deck here. 150 Watts peak. Nothing serious, just so I can have some sort of other entertainment.

Now about that clock. Just hold the H/dat M/dat buttons together? What does the Memo button do?

06-08-2006, 03:55 PM
Hold one button, push the other to adjust the number.

The memo button makes the clock ding on the hour so you remember to flip to CBC to listen to the news. Rather useless really.

06-08-2006, 04:02 PM
Thanks! Both problems solved! Now it's on to finding fenders and a stock shifter.

06-08-2006, 05:05 PM
Not trying to intrude, but I got new aftermarket fenders from Auto Parts Extra for $74 each plus shipping. About $210 in total for two. They will not fit as good as OEM, but cheap and not rusted. :p