Operation CHARM: Car repair manuals for everyone.

Electrical Diagnosis, Location & Description

ELECTRICAL DIAGNOSIS
RETAILER INSTALLED SECURITY
SYSTEM

FUSES

IP BATT Fuse

Location:
Underhood junction block

Type:
30A Maxifuse

Feeds:
Circuit 1936

If one of the following systems is operating normally, the fuse is most likely good.

^ Headlamp switch

^ Dome lamp

^ Remote mirror switch

^ Map lights

^ Power door lock relay

^ Radio

If the fuse is blown, determine the cause of the blown fuse and repair.

Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

IGN 4 Fuse

Location:
Underhood junction block

Type:
30A Maxifuse

Feeds:
Circuit 1932

If one of the following systems is operating normally, the fuse is most likely good:

^ Cluster

^ Windshield wipers

^ Radio

^ Turning signals

^ Hazard

^ Chime module

^ Passive restraint

^ Perf/Norm switch LED

^ Back-up lamp

^ Fuel injector(s)

^ Powertrain control module (PCM)

^ Distributorless ignition system (DIS)

^ Exhaust gas recirculation (EGR)

^ Auto trans relay

If the fuse is blown, determine the cause of the blown fuse and repair.

Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

PARK Fuse

Location:
I/P junction block

Type:
10A Minifuse

Feeds:
Circuit 240

If the following system is operating, the fuse is most likely good:

^ All lighting (except for high/low beam headlamps)

If the fuse is blown, determine the cause of the blown fuse and repair. Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

IGN 1 Fuse

Location:
I/P junction block

Type:
10A Minifuse

Feeds:
39, 39A, 39C, and Power Distribution

If one of the following circuits is operating normally, the fuse is most likely good:

^ Perf/Norm switch LED

^ Passive restraint control module

^ Instrument cluster

If the fuse is blown, determine the cause of the blown fuse and repair.

Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

BODY Fuse

Location:
I/P junction block

Type:
10A Minifuse

Feeds:
Circuit 340, 340A, 340B, 340C, 340F

If one of the following systems is operating normally, the fuse is most likely good:

^ Dome lamp

^ Cargo lamp switch

^ Remote mirror switch

^ Map Light

If the fuse is blown, determine the cause of the blown fuse and repair.

Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

Security System Main Fuse

Location:
Security system main harness

Type:
5A BUSS fuse

Feeds:
Circuit 340XX

If the following system is operating normally, the fuse is most likely good:

^ Security system

If the fuse is blown, determine the cause of the blown fuse and repair.

Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

Security System Park Fuse

Location:
Security system main harness

Type:
20A BUSS fuse

Feeds:
340

If the following system is operating normally, the fuse is most likely good:

^ Security system parking lamp flash

If the fuse is blown, determine the cause of the blown fuse and repair.

Replace fuse as needed.

If this component is good, go to the next item indicated on the chart.

GROUNDS

Circuit 155:

Location:
Connects security system module pin B5 to Chassis ground at I/P H-Brace.

Type:
Ring terminal

Check for OPENS/SHORTS. Check for proper torque at 13 mm bolt at left lower H-brace support (25 N-m [18 lbs.ft.]).

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 155ZZ

Location:
Connects left body splice pack connector cavity A to chassis ground point N.

Type:
Black 18 gage wire.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

POWER CIRCUITS

Circuit 1936

Location:
Connects the underhood junction block connector cavity A to the I/P junction block connector cavity F6.

Type:
Red/White 14 gage wire.

Function:
This circuit supplies battery voltage to the I/P junction block.

Check for OPENS/SHORTS.

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 1932

Location:
Connects the underhood junction block connector cavity C to the Ignition switch connector cavity A.

Type:
Red/Lt Green 14 gage wire

Function:
This circuit supplies battery voltage to the Ignition switch.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 340

Location:
Connects the I/P junction block connector cavity F7 to the Security system module connector cavity B1 through a 5A fuse and to the security system module connector cavity A8 through a 20A fuse.

Type:
Red/Black 20 gauge wire

Function:
This circuit supplies fused battery voltage to the Security system module.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 39

Location:
Connects I/P junction block connector cavity E2 to Security system module connector cavity A4.

Type:
Yellow 20 gage wire

Function:
This circuit supplies ignition voltage to the Security system module.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 953

Location:
Connects Security system module connector cavity B6 to Security system valet switch connector cavity B.

Type:
Black 20 gage wire.

Function:
This circuit supplies a signal from the Security system valet switch to the Security system module to indicate the system mode.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 156 (Up-Level System Only)

Location:
Connects I/P junction block connector cavity B3 to Security system module connector cavity A1.

Type:
White 20 gage wire.

Function:
This circuit provides a signal from the chime module to the Security system module to indicate that a door is open. This circuit also sends a signal from the Security system module to the chime module to activate the dome lamp.

Check for OPEN/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 156A (Up-Level system only)

Location:
Connects I/P junction block connector cavity B3 to Dome lamp connector cavity A.

Type:
White 22 gage wire.

Function:
This circuit provides a signal from the chime module or the Security system module to activate the dome lamp.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 950

Location:
Connects Security system module connector cavity A3 to negative side of LED.

Type:
Green 20 gage wire.

Function:
This circuit provides the negative path for the LED.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 951

Location:
Connects Security system module connector cavity B2 to positive side of LED.

Type:
Brown 20 gage wire.

Function:
This circuit provides voltage to the positive side of the LED.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 194 (Up-Level System Only)

Location:
Connects Security system module connector cavity A6 through a splice pack to door lock relay connector cavity A.

Type:
Black 20 gage wire-1991
Black 22 gage wire-1992
BLK/WHT 22 gage wire-92 Mid-Year.

Function:
This circuit supplies voltage to the unlock side of the interior door lock switches.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 195 (Up-Level System Only)

Location:
Connects Security system module connector cavity A7 through a splice pack to door lock relay connector cavity F.

Type:
Lt Blue 20 gage wire-1991
Lt. Blue 22 gage wire-1992

Function:
This circuit supplies voltage to the lock side of the interior door lock switches.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.

Circuit 28/28C

Location:
Connects Security system module connector cavity A5 through a splice pack to I/P junction block connector cavity A4.

Type:
Black/Green 20 gage wire.

Function:
This circuit provides voltage from the Security system module to activate the horn.

Check for OPENS/SHORTS

Repair as needed.

If this component is good, go to the next item indicated on the chart.