Put a Nokia car kit in a '98 5er
Posted by DRaven on September 11, 2001 at 06:35:22:

This project seemed to grow while I wasn't looking. The goal was to install
the car kit for a Nokia 5100/6100 series phone into my wife's 1998 528i. I
wanted use only the cars existing wiring and not pull a lot of interior
panels from the car.

I purchased the following BMW components:
Microphone 84 31 8 380 338
Antenna Base 84 50 6 907 304
Connector Box 84 50 6 907 306
Dual Band Antenna 84 50 6 907 302

Most every BMW I have seen made in the last 5 years has come pre-wired for a
phone. The antenna cables are there, the handset cables are there, the
microphone cables are there, and the transceiver cables are there. The
trick was to identify and use these cables to interface to my Nokia kit.

I chose to mount the cradle in the factory location in the center console.
(pic 13) I used a male header I bought from Radio Shack (PN 910-1530) to
make a cable to interface with the wiring under the armrest (you can just
splice wires if you want to here). I mounted and connected the Nokia
control unit here under the console. I used two short pieces of duplex
(Speaker) wire and one each of a mini (Radio Shack PN 274-0286) and super
mini (PN 274-0289) mono jacks to connect the Mic and Speaker ports on the
Nokia unit to the car wiring. The completed harness is shown in pic 9.

The BMW phone mounts in the trunk so most of the wiring terminates there on
a female DB-25 connector. (pic 3) I made an adapter (pic 16) to route the
Mic, Speaker, 12V Battery and Radio Mute up to the center console connector.
(pic 7) The car has two RG-58 coax cables in the trunk with the DB-25. One
goes to the center console and the other goes up the left side (US Drivers's
side) C-pillar. Connect theses two cables together in the trunk to complete
the cable run from the console to the C-pillar. The cable in the C-pillar
is doubled back on itself and needs to be unfurled and routed over to the
center of the rear glass to connect to the factory antenna connector box.

I have included the complete pinout of both my adapters and the car wiring
below. Hope this helps any who wanted another option than BMW/Motorola.

Center Console
AMP 18-pin Female
1 Blue Pin 11 of DB-25 in trunk
2 White/Red Pin 12 of DB-25 in trunk
3 White/Green Pin 18 of DB-25 in trunk
4 Yellow/Red Pin 1 of DB-25 in trunk
5 Not Used
6 Blue/Green Pin 6 of DB-25 in trunk
7 Yellow Pin 23 of DB-25 in trunk
8 Violet Ignition 12V
9 Yellow/Black Battery 12V
10 Brown/White Ignition 12V
11 White Unknown
12 Not Used
13 Orange Pin 8 of DB-25 in trunk
14 White/Grey Pin 21 of DB-25 in trunk
15 Grey Illumination
16 White/Blue Pin 7 of DB-25 in trunk
17 Brown Ground
18 White/Black Pin 24 of DB-25 in trunk

Left Side Trunk
Female DB-25
1 Yellow/Red Pin 4 of AMP in center console
2 Not Used
3 Brown Ground
4 Red Battery 12V
5 Violet Ignition 12V
6 Blue/Green Pin 6 of AMP in center console
7 White/Blue Pin 16 of AMP in center console
8 Orange Pin 8 of AMP in center console
9 Not Used
10 Black Radio Mute (Ground to Mute)
11 Blue Pin 1 of AMP in center console
12 White/Red Pin 2 of AMP in center console
13 Not Used
14 White Microphone (+)
15 Brown/White Microphone (-)
16 Red Battery 12V
17 Brown Ground
18 White/Green Pin 3 of AMP in center console
19 Yellow/Black Speaker (-)
20 Brown/Black Shield for Microphone
21 White/Grey Pin 14 of AMP in center console
22 Not Used
23 Yellow Pin 7 of AMP in center console
24 White/Black Pin 18 of AMP in center console
25 Green Speaker (+)

Male connector for
AMP 18-pin connector
located in center console
1 Speaker (-)
2 Speaker (+)
3 Yellow from Nokia Harness (Radio Mute)
4 Not Used
5 Not Used
6 Mic (-)
7 Not Used
8 Blue from Nokia Harness (Ingnition 12V)
9 Not Used
10 Not Used
11 Not Used
12 Not Used
13 Red from Nokia Harness (Battery 12V)
14 Not Used
15 Not Used
16 Mic (+)
17 Black from Nokia Harness (Ground)

DB-25 Adapter for Trunk
1 Not Used
2 Not Used
3 Not Used
4 Loop to Pin 8 (Battery 12V)
5 Not Used
6 Loop to Pin 15 (Mic -)
7 Loop to Pin 14 (Mic +)
8 Loop to Pin 4 (Battery 12V)
9 Not Used
10 Loop to Pin 18 (Radio Mute)
11 Loop to Pin 19 (Speaker -)
12 Loop to Pin 25 (Speaker +)
13 Not Used
14 Loop to Pin 6 (Mic +)
15 Loop to Pin 7 (Mic -)
16 Not Used
17 Loop to Pin 20 (Ground for Mic Shield)
18 Loop to Pin 10 (Radio Mute)
19 Loop to Pin 11 (Speaker -)
20 Loop to Pin 17 (Ground for Mic Shield)
21 Not Used
22 Not Used
23 Not Used
24 Not Used
25 Loop to Pin 12 (Speaker +)

Try this at your own risk and other disclaimer-type language applies.