PAC Car Stereo Video Installation Parts Guide

1. Black 18ga. wire - Power supply ground. Connect this wire to the

same ground point where the aftermarket ampliﬁ er power supply

ground is grounded (Fig. 1). Extend wire if necessary. This wire

must be grounded before plugging in RCA cables. Failure to do

so may result in aftermarket ampliﬁ er and/or interface to become

damaged.

Green 22ga. wire - ground the Green wire to chassis ground if you

want the C2A-GM24 outputs to fade out when you fade to the front

on the radio.

Blue 22ga. wire - ground the Blue wire to chassis ground if you want

the C2A-GM24 outputs to fade out when you fade to the rear on the

radio. If you want non fading outputs, insulate both the Blue and

Green 22ga. wire separately.

2. Remove factory 24 pin connector from head unit. Insert the C2A-

GM24 male plug into the radio. Plug factory 24 pin male connector

into the C2A-GM24 female connector as shown in Fig.1 below.

3. Plug RCA cables from aftermarket ampliﬁ er into C2A-GM24. Be

sure that the C2A-GM24 black wire is grounded ﬁ rst.

4. Connect the Blu/Wht wire from C2A-GM24 to remote input of

aftermarket ampliﬁ er. Maximum current output on the Blu/Wht wire

is 300 ma.

5. Follow ampliﬁ er instructions for connecting speaker wires and power

to aftermarket ampliﬁ er.

C2A-GM24

Add an Amp Interface

Instructions

  

The C2A-GM24 allows you to add a 2 channel aftermarket ampliﬁ er

for GM vehicles with Class 2 data bus . What makes the C2A-GM24

unique is that is takes the ﬁ xed level audio signal from the factory head

unit before it gets to the Bose® ampliﬁ er and gives you a variable

output. The C2A-GM24 outputs are digitally controlled by the head

unit’s volume knob. You get full range audio signal, not a Bose®

speciﬁ c equalized output, high passed or low passed output.

• Great for adding subwoofer ampliﬁ ers.

• 2 channel RCA outputs with left and right level adjustments for

matching aftermarket ampliﬁ er/speakers audio signal to factory

speakers.

• User can select wither the C2A-GM24 will fade out when radio is

faded forward/back or can be selected to be non-fading.

• +12 volt 300 ma. remote turn-on output.

• Plug & Play, no hard wiring required.

Installation

RDS

PWR

DISP

BAND

TAPE

DISC

INFO

SEEK

TYPE

TRAF

AUTO

VOL

SEEK

SCAN

VOL

TUNE

C2A-GM24

General Motors Class II Add an Amp to

BOSE Fixed Audio Level Headunits

2 Channel Non-Fading RCA Outputs with 12v Remote Turn-on

Left

Right

Sensitivity Adjustment

Fig. 1

Insert these two plugs in between the factory headunit

and factory 24 pin plug. DO NOT plug in at factory amplifier.

Aftermarket

amplifier

blue/wht: +12 volt remote output

Factory 24 pin wire harness at radio, not amplifier.

Blue

Green

300ma. maximum output

Black wire

Ground at same point as amplifier ground

Factory Radio

Testing

1. Turn ignition on. Turn radio on and set to minimum volume.

Aftermarket ampliﬁ er will be off at minimum volume. Turn volume up

1 notch and aftermarket ampliﬁ er will turn on within 2 seconds.

2. Adjust radio volume up 2 to 3 clicks so audio can be heard. Adjust

the levels on the C2A-GM24 to about 1/4 clockwise to increase

output.

3. Adjust ampliﬁ er’s gain adjustments until music is balanced with the

factory stereo system.

4. If the adjustments on the aftermarket ampliﬁ er is at minimum and the

music is louder than the factory system, turn the gains on the C2A-

GM24 down until balanced.

5. If the adjustments on the aftermarket ampliﬁ er is at maximum and

the music is lower than the factory system, turn the gains on the

C2A-GM24 up until balanced. If you still can not get the volume up

to factory sound level, check to see if the aftermarket ampliﬁ er has a

sensitivity switch to accept sources with less voltage output.

6. If the Blue or Green wires are not grounded, the outputs will not vary

in volume as the radio is faded to the front or rear. However, the

C2A-GM24 is designed to turn off the outputs when you fade to the

last couple of notches in either the front or rear position.

7. If the Green wire is grounded and you start to fade to the front, the

C2A-GM24 outputs will fade out. If the Blue wire is grounded when

you start to fade to the rear, the C2A-GM24 outputs will fade out. The

C2A-GM24 is designed to turn off the outputs when you fade to the

last couple of notches.

Note:

1. The C2A-GM24 must be inserted at factory radio. It will not work at

the factory ampliﬁ er.

2. When ever you adjust the volume of the radio to minimum, the

aftermarket ampliﬁ er will turn off. When you turn the volume up from

minimum, there will be a delay before the ampliﬁ er turns on and

sound is heard.

Speciﬁ cation:

Frequency Response - 20Hz - 20kHz.

Maximum signal voltage output - 1.3 volts +/- 5%.

J1850

Class 2

VPW

Class 2

J1850

100011101111001001101100

111010000110110111001100

Arbitration

EOD

CRC

100011101111001001101100

111010000110110111001100

Class 2

J1850

Description