GMC Topkick (2003-2010) fuses and relays

Fuse box diagram (location and assignment of electrical fuses and relays) for GMC Topkick (2006, 2007, 2008, 2009).

Fuse box diagram: GMC Topkick (2003-2010)

2006
2007
2008, 2009

Fuse box location

Instrument panel fuse box

There are two instrument panel fuse blocks located behind the instrument panel on the passenger’s side of the vehicle.

Engine compartment fuse box

Both underhood fuse blocks are located in the engine compartment, on the passenger’s side of the vehicle.
To access the fuse blocks, gently squeeze both sides of the cover to unlatch the tabs at the top. Then, unsnap both attachments at the bottom and remove the cover.

Fuse box diagrams 2006

Primary Underhood Fuse Block

Under-hood fuse box diagram: GMC Topkick (2006)

Assignment of the fuses in the Primary Underhood Fuse Block (2006)
FuseUsage
RR DEFOGRear Defog
ENG 1Engine 1
ENG 3Engine 3
PCM-BPowertrain Control Module
BLANKNot Used
ENG 4Engine 4
ENG 2Engine 2
HTD FUELHeated Fuel
BLANKNot Used
BLANKNot Used
O2AEmissions
A/C COMPAir Conditioning Compressor
ABS 1Anti-lock Brake System 1
ABS 2Anti-lock Brake System 2
ABS 3Anti-lock Brake System 3
ENGINEEngine
E/A PUMPElectronic/Automatic Pump
HORNHorn
NOTE 2L18 Fuel, LG4 Powertrain Control Valve, LG5 Electronic Control Module
NOTE 3L18 Fuel, LG4 Powertrain Control Valve, LG5 Electronic Control Module
STUD ASpare
STUD BSpare
Relay
NOTE 1LG4 Powertrain Control Valve, L18 Fuel Pump, LG5 Heated Fuel
IGN BIgnition
STARTERStarter
HORNHorn
IGN AIgnition
PTO/ECUPower Take-Off/Engine Control Unit "Diesel 7.8L DURAMAX
REVERSEReverse
NEUTRAL STARTNeutral Start

Secondary Underhood Fuse Block

Secondary Underhood Fuse Block: GMC Topkick (2006)

Assignment of the fuses in the Secondary Underhood Fuse Block (2006)
FuseUsage
IGN 1Four-Wheel Drive Module
IGN 4Ignition 4
IGN 3Ignition 3
BATT/HAZBattery/Hazard Warning Flashers
HEADLAMPHeadlamps
LIGHTINGInterior/Exterior Lamps
HVACClimate Control System
NOTEC4/C5 Electric Brake, C6/C7/C8 Brake Lamps

Instrument panel, box1

Instrument panel fuse box #1 diagram: GMC Topkick (2006)

Assignment of the fuses in the Instrument panel fuse box 1 (2006)
Circuit BreakerUsage
1Stoplamps
2Center High-Mounted Stoplamp
3Parking Lamps
4Powertrain Control Module
5Auxiliary Wiring
6Heater/Air Conditioning
7Hazard Warning Flashers
8Power Post
9Courtesy Lamps
10Warning Lights, Gages and Indicators
11Starter
12Rear Axle/Four-Wheel-Drive
13Trailer Turn Signals/Hazard Warning Flashers
14Radio/Chime
15Daytime Running Lamps
16Airbag System
17Exterior/lnterior Lamps
18Parking Brake
19Accessory Power
20Ignition 4
21Sidemarker Lamps
22Turn Signal/Backup Lamps
23Transmission
24Hydraulics/Air Brake
ASpare
BSpare

Instrument panel, box 2

Instrument panel fuse box #2 diagram: GMC Topkick (2006)

Assignment of the fuses in the Instrument panel fuse box 2 (2006)
FuseUsage
HTD/MIRRHeated Mirrors
BlankNot Used
RT TRN TRLRPassenger's Side Trailer Turn Signal
BlankNot Used
LT TRN TRLRDriver's Side Trailer Turn Signal
BlankNot Used
BRKBrake Warning Lamp
RT PRKPassenger's Side Parking Lamps
BlankNot Used
BlankNot Used
BlankNot Used
LT PARKDriver's Side Parking Lamps
BlankNot Used
RT REAR TRN/STOPPassenger's Side Rear Turn Signal/Stoplamp
LT REAR TRN/STOPDriver's Side Rear Turn Signal/Stoplamp
RADIORadio
BlankNot Used
BlankNot Used
BlankNot Used
PWR WNDWPower Windows
Relay
ECU/PTOEngine Control Unit/Power Take-Off "Diesel 7.8 DURAMAX®
BRK LAMPC4/C5 Brake Lamps, C6/C7/C8 Tractor/Trailer Wiring
DRLDaytime Running Lamps
IGN-4Ignition
CHMSLCenter High Mounted Stop Lamp
MRK LTSSidemarker and Clearance Lamps

Fuse box diagrams 2007

Primary Underhood Fuse Block

Under-hood fuse box diagram: GMC Topkick (2007)

Assignment of the fuses in the Primary Underhood Fuse Block (2007)
FuseUsage
RR DEFOGRear Defog
ENG 1Engine 1
ENG 3Engine 3
PCM-BPowertrain Control Module
BLANKNot Used
ENG 4Engine 4
ENG 2Engine 2
HTD FUELHeated Fuel
BLANKNot Used
BLANKNot Used
O2AEmissions
A/C COMPAir Conditioning Compressor
ABS 1Anti-lock Brake System 1
ABS 2Anti-lock Brake System 2
ABS 3Anti-lock Brake System 3
ENGINEEngine
E/A PUMPElectronic/Automatic Pump
HORNHorn
NOTE 2L18 Fuel, LG4 Powertrain Control Valve, LG5 Electronic Control Module
NOTE 3L18 Fuel, LG4 Powertrain Control Valve, LG5 Electronic Control Module
STUD ASpare
STUD BSpare
Relay
NOTE 1LG4 Powertrain Control Valve, L18 Fuel Pump, LG5 Heated Fuel
IGN BIgnition
STARTERStarter
HORNHorn
IGN AIgnition
PTO/ECUPower Take-Off/Engine Control Unit 'Diesel 7.8L DURAMAX'
REVERSEReverse
NEUTRAL STARTNeutral Start

Secondary Underhood Fuse Block

Secondary Underhood Fuse Block: GMC Topkick (2007)

Assignment of the fuses in the Secondary Underhood Fuse Block (2007)
FuseUsage
IGN 1Four-Wheel Drive Module
IGN 4Ignition 4
IGN 3Ignition 3
BATT/HAZBattery/Hazard Warning Flashers
HEADLAMPHeadlamps
LIGHTINGInterior/Exterior Lamps
HVACClimate Control System
NOTEC4/C5 Electric Brake, C6/C7/C8 Brake Lamps

Instrument panel, box1

Instrument panel fuse box #1 diagram: GMC Topkick (2007)

Assignment of the fuses in the Instrument panel fuse box 1 (2007)
Circuit BreakerUsage
1Stoptamps
2Center High-Mounted Stoplamp
3Parlang Lamps
4Powertrain Control Module
5Auxiliary Wiring
6Heater/Air Conditioning
7Hazard Warning Flashers
8Power Post
9Courtesy Lamps
10Warning Lights, Gages and Indicators
11Starter
12Rear Axle/Four-Wheel-Drive
13Trailer Turn Signals/Hazard Warning Flashers
14Radio/Chime
15Daytime Running Lamps
16Airbag System
17Exterior/Interior Lamps
18Parlang Brake
19Accessory Power
20Ignition 4
21Sidemarker Lamps
22Turn Signal/Backup Lamps
23Transmission
24Hydraulics/Air Brake
ASpare
BSpare

Instrument panel, box 2

Instrument panel fuse box #2 diagram: GMC Topkick (2007)

Assignment of the fuses in the Instrument panel fuse box 2 (2007)
FuseUsage
BlankNot Used
RT PRKPassenger's Side Parking Lamps
BlankNot Used
BlankNot Used
LT PARKDriver’s Side Pairing Lamps
RT REAR TRN/STOPPassenger's Side Rear Turn Signal/Stoplamp
LT REAR TRN/STOPDriver’s Side Rear Turn Signal/Stoplamp
RADIORadio
BlankNot Used
BlankNot Used
PWRWNDWPower Windows
Relay
ECU/PTOEngine Control Unit/Power Take-Off 'Diesel 7.8 DURAMAX
BRK LAMPC4/C5 Brake Lamps, C6/C7/C8 Tractor/Trailer Wiring
DRLDaytime Running Lamps
IGN-4Ignition
CHMSLCenter High Mounted Stop Lamp
MRKLTSSidemarker and Clearance Lamps
HTD/MIRRHeated Mirrors
HTRDiesel Heated Fuel
RT TRN TRLRPassenger's Side Trailer Turn Signal
BlankNot Used
LT TRN TRLRDriver’s Side Trailer Turn Signal
BlankNot Used
BlankNot Used
BlankNot Used

Fuse box diagrams 2008, 2009

Primary Underhood Fuse Block

Under-hood fuse box diagram: GMC Topkick (2008, 2009)

Assignment of the fuses in the Primary Underhood Fuse Block (2008, 2009)
FuseUsage
RR DEFOGRear Defog
ENG 1Engine 1
ENG 3Engine 3 (L18/LF6/LF8)
PCM-BPowertrain Control Module
TCMTransmissions (LF8)
ENG 4Engine 4 (LMM/LF6/LF8)
ENG 2Engine 2 (L18/LMM)
HTD FUELHeated Fuel (LMM)
BLANKNot Used
BLANKNot Used
NOTE 3Fan Relay (LMM), Emissions (L18)
A/C COMPAir Conditioning Compressor
ABS 1Anti-lock Brake System 1
ABS 2Anti-lock Brake System 2
ABS 3Anti-lock Brake System 3
ENGINEEngine
E/A PUMPElectronic/Automatic Pump
HORNHorn
NOTE 2Fuel (L18/LMM), Electronic Control Module (LF6)
NOTE 3Electronic Control Module (LF6)
STUD ASpare
STUD BSpare
Relay
NOTE 1LMM/L18 Fuel Pump Relay
IGN B RELAYIgnition Relay
STARTER RELAYStarter Relay
HORN RELAYHorn Relay
IGN A RELAYIgnition Relay
PTO/ECU RELAYPower Take-Off/Engine Control Unit (*Diesel 7.8L LF8)
REVERSE RELAYReverse Relay
FAN RELAYFan Relay (LMM)

Secondary Underhood Fuse Block

Secondary Underhood Fuse Block: GMC Topkick (2008, 2009)

Assignment of the fuses in the Secondary Underhood Fuse Block (2008, 2009)
FuseUsage
IGN 1Ignition 1
IGN 4Ignition 4
IGN 3Ignition 3
BATT/HAZBattery/Hazard Warning Flashers
HEADLAMPHeadlamps
LIGHTINGInterior/Exterior Lamps
HVACClimate Control System
NOTEC4/C5 Electric Brake, C6/C7/C8 Brake Lamps

Instrument panel, box 1

Instrument panel fuse box #1 diagram: GMC Topkick (2008, 2009)

Assignment of the fuses in the Instrument panel fuse box 1 (2008, 2009)
Circuit BreakerUsage
1Stoplamps
2Not Used
3Parking Lamps
4Powertrain Control Module
5Auxiliary Wiring
6Heater/Air Conditioning
7Hazard Warning Flashers
8Power Post
9Courtesy Lamps
10Warning Lights, Gages and Indicators
11Starter
12Rear Axle/Four-Wheel-Drive
13Trailer Turn Signals/Hazard Warning Flashers
14Radio/Chime
15Daytime Running Lamps
16Airbag System
17Exterior/lnterior Lamps
18Parking Brake
19Accessory Power
20Ignition 4
21Sidemarker Lamps
22Turn Signal/Backup Lamps
23Transmission
24Hydraulics/Air Brake
ASpare
BSpare

Instrument panel, box 2

Instrument panel fuse box #2 diagram: GMC Topkick (2008, 2009)

Assignment of the fuses in the Instrument panel fuse box 2 (2008, 2009)
FuseUsage
BlankNot Used
RT PRKPassenger's Side Parking Lamps
BlankNot Used
BlankNot Used
LT PARKDriver’s Side Parking Lamps
RT REAR TRN/STOPPassenger’s Side Rear Turn Signal/Stoplamp
LT REAR TRN/STOPDriver’s Side Rear Turn Signal/Stoplamp
RADIORadio
BlankNot Used
BlankNot Used
PWR WNDWPower Windows
Relay
ECU/PTOEngine Control Unit/Power Take-Off "Diesel 7.8 DURAMAX®
BRK LAMPC4/C5 Brake Lamps, C6/C7/C8 Tractor/Trailer Wiring
DRLDaytime Running Lamps
IGN-4Ignition
CHMSLCenter High Mounted Stop Lamp
MRK LTSSidemarker and Clearance Lamps
HTD/MIRRHeated Mirrors
HTRDiesel Heated Fuel
RT TRN TRLRPassenger's Side Trailer Turn Signal
BlankNot Used
LT TRN TRLRDriver's Side Trailer Turn Signal
BlankNot Used
BlankNot Used
BlankNot Used
GMC Topkick (2003-2010) fuses and relays March 30, 2019 admin