PAC Factory GM 21 pin plug, Wiring the OEM-2and aftermarket stereo to a GM, GM21B, GM21A

Wiring the OEM-2 and aftermarket stereo to a GM

factory Bose Premium Sound System

Mobile Audio Interfacing Equipment

Important!

If you are using the supplied wire harness from Crutchfi eld, or other aftermarket wire harness either from Metra, Scosche or American International, you can not connect the audio signal wires of the supplied wire harness to the OEM-2 color for color (you may however, connect the red, black, blue, orange, and yellow wire color for color). The wire harness supplied by Crutchfi eld or other above mentioned wire harnesses are not designed for Bose Premium Sound Systems. You will need to trace the factory wire colors and match them over to the aftermarket harness. Connect the OEM-2 outputs according to the chart.

The factory wire colors given are typical of most GM vehicles with a Bose Premium Sound System. If the colors do not match up, you will need to obtain a wiring diagram of your vehicle from a dealer. In some vehicles the audio common wires could have a striped wire.

NOTES: 4 possible GM plug confi gurations.

GM21 and GM21A: has a bare shield wire for both front

11

12

13

14

15 16

17

18

19

20

a rear speakers.

GM21B: has no bare shield wire and has common wires

for front and rear.

1

2

3

4

5

6 7

8

9

10

GM21C: has a positive and negative wire for each

speaker.

Use the shield wire(s) as a guide to determine which

Factory GM 21 pin plug

chart to use.

Viewed from pin side not wire side

GM21

GM21B

Factory plug.

Factory plug.

Connect these wires to

OEM-2

Connect these wires to

OEM-2

1

= front audio shield, bare wire

black wire

1

= n/a

n/a

2

= left front positive (LF+), tan

wht wire

2

= left front positive (LF+), tan

wht wire

3

= right and left front common (-), lt. grn

wht/blk and gry/blk wires

3

= n/a

n/a

4

= right front positive (RF+), dark green

gry wire

4

= right front positive (RF+), dark green

gry wire

5

= chassis ground, black

black wire

5

= chassis ground, black

black wire

6

= illumination/dimmer, gray

orange wire

6

= illumination/dimmer, gray

orange wire

7

= n/a

n/a

7

= n/a

n/a

8

= remote turn on, pink

blue/wht

8

= remote turn on, pink

blue/wht

9

= 12 volt ignition/switched (+12), yellow

red wire

9

= 12 volt ignition/switched (+12), yellow

red wire

10 = 12 volt battery/constant (+12), orange

yellow wire

10 = 12 volt battery/constant (+12), orange

yellow wire

17 = rear audio shield, bare wire

black wire

17 = audio common

prp/blk, wht/blk, gry/blk and grn/blk wires

18 = right rear positive (RR+), dark blue

purple wire

18 = right rear positive (RR+), dark blue

purple wire

19 = right and left rear common (-), yellow

prp/blk and grn/blk wires

19 = n/a

n/a

20 = left rear positive (LR+), dark brown

grn wire

20 = left rear positive (LR+), dark brown

grn wire

GM21A

		Factory plug.
		Connect these wires to	OEM-2
1	= left front positive (LF+), tan		wht wire
2	= right and left front common (-), lt. grn		wht/blk and gry/blk wires
3	= right front positive (RF+), dark green		gry wire
4	= front audio shield, bare wire		black wire
5	= chassis ground, black		black wire
6	= illumination/dimmer, gray		orange wire
7	= n/a		n/a
8	= remote turn on, pink		blue/wht
9	= 12 volt ignition/switched (+12), yellow		red wire
10		= 12 volt battery/constant (+12), orange	yellow wire
17		= right rear positive (RR+), dark blue	purple wire
18		= right and left rear common (-), yellow	prp/blk and grn/blk wires
19		= left rear positive (LR+), dark brown	grn wire
20		= rear audio shield, bare wire	black wire

GM21C

		Factory plug.
		Connect these wires to	OEM-2
1	= left front negative (LF-), gray		wht/blk wire
2	= left front positive (LF+), tan		wht wire
3	= right front negative (RF-), dark green		gry/blk wire
4	= right front positive (RF+), lt. green		gry wire
5	= chassis ground, black		black wire
6	= illumination/dimmer, gray		orange wire
7	= n/a		n/a
8	= remote turn on, pink		blue/wht
9	= 12 volt ignition/switched (+12), yellow		red wire
10		= 12 volt battery/constant (+12), orange	yellow wire
17		= right rear negative (RR-), lt. blue	prp/blk wire
18		= right rear positive (RR+), dark blue	purple wire
19		= left rear negative (LR-), yellow	grn/blk wire
20		= left rear positive (LR+), brown	grn wire

Document and Material Disclaimer: All information, including photos and illustrations, in these pages is believed to be correct and reliable. The information contained in these pages is given as general information for the installation of audio accessories into mobile and/or vehicle applications. PACIFIC ACCESSORY CORPORATION shall not be held liable for any damages and/or injuries resulting from the use of information contained in these pages. All information contained in these pages should be checked and verifi ed with appropriate test equipment to assure the safety and proper operation of equipment installed and the vehicle itself.

Copyright © 2002 Pacifi c Accessory Corporation.

11-08-02	Pacifi c Accessory Corporation - 1502 S. Santa Fe Street, Santa Ana, CA 92705
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