GM Service Manual Online
For 1990-2009 cars only
Table 1: Individual Conductors
Table 2: Individual Conductors

Park/Side Marker and Tail Lamps

The park/side marker and tail lamps are split between the following 4 fuses:

    • The FR PRK
    • The LR PRK
    • The RR PRK
    • The TRL PRK

These fuses receive voltage from the park lamp relay. When the headlamp and panel dimmer switch is in the auto position, the body control module (BCM) controls the relay by grounding CKT 1080 based on the input of the ambient light sensor. The park LPS fuse supplies battery positive voltage (B+) to the relay at all times.

When the headlamp and panel dimmer switch is in the PARK position, the relay is by passed through the INT PRK fuse. Current flows from the PARK LPS fuse through the headlamp and panel dimmer switch to the INT PRK fuse in order to feed the following fuses:

    • The FR PRK
    • The LR PRK
    • The RR PRK
    • The TRL PRK

Stop Lamps

The STOP LPS fuse supplies battery positive voltage (B+) at all times to the stoplamp switch. When the brake pedal is depressed, CKT 17 supplies battery positive voltage (B+) to the VEH STOP and the CHMSL fuses causing the lamps to light through CKT 1320 and CKT 1620.

Turn Signal lamps

When the ignition switch is in the run position and the turn/hazard switche is in a turn position, voltage is supplied from the TURN fuse through the turn/hazard switch to the turn/hazard flasher, CKT 1696. The flasher then passes current back to the turn/hazard switch in an intermittent on and off pattern, CKT 1697. From the turn/hazard switch, voltage is supplied to the LT TURN or the RT TURN fuse, CKT 14 or CKT 15. From the fuse voltage is supplied to the respective lamps on CKT 2114 left or CKT 2115 right.

Hazard Lamps

When the turn/hazard switch is in the hazard position, voltage is supplied from the HAZ LP fuse at all times through the turn/hazard switch to the turn/hazard flasher, CKT 1508. The flasher then passes current back to the turn/hazard switch in an intermittent on off pattern, CKT 1697. From the turn/hazard switch, voltage is supplied to the LT TURN and the RT TURN fuse, CKT 14 or CKT 15. From the fuse, voltage is supplied to the respective lamps on CKT 2114 left and CKT 2115 right.

Trailer Wiring

Important: The trailer harness and fuses must be connected to the underhood bussed electrical center (UBEC). The trailer harness circuits are identified in the following table. Please take note of the maximum current ratings of the circuits.

Stop lamps and turn signal lamps are similar to the above description with the exception of the following conditions:

    • From the stoplamp switch, voltage is supplied to the turn/hazard switch on CKT 17 (WHT).
    •  From the turn/hazard switch, voltage is supplied to the TRL L Turn or the TRL R Turn fuse on CKT 18 (YEL) or CKT 19 (DK GRN).
    • From the fuse, voltage is supplied to the trailer connector

Individual Conductors

CKT ID Number

Color

Description

22 (HD)

WHT

Ground 70 A maximum current (HD)

22 (LD)

WHT

Ground 25 A maximum current (LD)

47

DK BLU

Trailer brake controller switch output

142

RED

Fuse output - Battery 22.5 A maximum current

742

RED

Fuse output - Battery 30 A maximum current

1324 (LD)

LT GRN

Fuse output - backup lamps 7.5 A maximum current (LD)

1624 (HD)

LT GRN

Fuse output - trailer backup lamps 7.5 A maximum current (HD)

1618

YEL

Fuse output - trailer turn/stop LH rear 7.5 A maximum current

1619

DK GRN

Fuse output - trailer turn/stop RH rear 7.5 A maximum current

1620

LT BLU

Fuse output - trailer CHMSL 7.5 A maximum current

2109

BRN

Fuse output - trailer park lamp 7.5 A maximum current

Z82 - Trailering Pigtail - Electrical Installation Instructions

Important: Please consult your brake controller instruction on how to wire your controller with these circuits.

  1. The brake controller pigtail and 40A B+ trailering Maxi-fuse has been provided with the HD trailering option.
  2. Plug in the 6 Way connector into the mid bussed electrical center (MBEC) which is located on the upper left of the drivers footwell.

  3. Plug-in the 40Amp B+ trailering Maxi-fuse in stud #1 location of underhood bussed electrical center (UBEC).
  4. The brake controller jumper blunt cut circuits have been identified as follows:

Individual Conductors

CKT ID #

Color

Description

47

DK BLU

Trailer Brake Controller Switch Output

142

RED

Fused Trailer Brake Controller Battery Feed

1620

LT BLU

Vehicle Stop Lamp Switch to Brake Controller Input

1850

BLK

Brake Controller Ground

2409

BRN

Brake Controller Illumination