Under Hood Fuse And Relay Box Diagram (1999 4.6L, 5.4L Ford F150, F250 Light Duty)

Location and descriptions of the fuses and relays of the under-hood fuse box for 1997-1998 Ford F150, F250 and F350.

The under-hood fuse/relay box is known as the Battery Junction Box in the Ford service/repair literature.

Fuses
#	Amps	Fuse Name/Description
1	25 Amps	Auxiliary Power Socket
2	30 Amps	PCM Power Relay
3	30 Amps	Headlamp Relay Main Light Switch Multi-Function Switch
4	15 Amps	Air Suspension
5	20 Amps	Trailer Tow Backup Relay Trailer Tow Running Lamp Relay
6	15 Amps	Park Lamps Relay Main Light Switch
7	20 Amps	Horn
8	15 Amps	Power Door Locks
9	15 Amps	Daytime Running Lamps (DRL) Resistor Fog Lamps Relay
10	20 Amps	Fuel Pump Relay
11	20 Amps	Alternator
12	--	NOT USED
13	--	NOT USED
14	--	NOT USED
15	--	NOT USED
16	--	NOT USED
17	--	NOT USED
18	15 Amps	Powertrain Control Module Fuel Injectors Fuel Pump MAF Sensor
19	10 Amps	Trailer Tow Stop Right Turn Light
20	10 Amps	Trailer Tow Stop Left Turn Light
21	--	NOT USED
22	--	NOT USED
23	15 Amps	Powertrain Control Module (PCM) Oxygen Sensors EVAP Canister Vent
24	15 Amps	Powertrain Control Module (PCM) Automatic Transmission CMS Sensor

Fuses
#	Amps	Fuse Name/Description
101	30 Amps	Trailer Tow Battery Charge Relay
102	20 Amps	Rear Wheel Antilock Brake Module (2W ABS only)
	50 Amps	4 Wheel Antilock Brake Module (4W ABS only)
103	30 Amps	Junction Block Fuse 2 (Dash Fuse Box)
104	30 Amps	4x4 Shift Motor & Clutch
105	40 Amps	Blower Relay
106	--	NOT USED
107	--	NOT USED
108	30 Amps	Trailer Adapter (Electric Brake Control)
109	50 Amps	Air Suspension Compressor Relay
110	30 Amps	Power Windows ACC Delay Relay
111	50 Amps	Ignition Switch Battery Feed (Pins B4 and B5)
112	30 Amps	Power Seat Control Switch
113	50 Amps	Ignition Switch Battery Feed (Pins B1 and B3)
114	--	NOT USED
115	--	NOT USED
116	--	NOT USED
117	--	NOT USED
118	--	NOT USED

Relays
#	Fuse Name/Description
R1	Trailer Tow Park Lamp Relay
R2	Front Wiper Run/Park Relay
R3	Trailer Tow Backup Lamp Relay
R4	A/C Clutch Relay
R5	Horn Relay
R6	Fog Lamp Relay
R7	Front Washer Pump Relay
R8	NOT USED
R9	Front Wiper HI/LO Relay

Relays
#	Fuse Name/Description
R01	Fuel Pump Relay
R02	Trailer Tow Battery Charge Relay
R03	Rear Air Suspension Relay
R04	Powertrain Control Module (PCM) Relay

APPLIES TO: This fuse and relay chart applies to the following vehicles:

• 4.6L V8 Ford F150: 1999.
• 5.4L V8 Ford F150: 1999.
• 4.6L V8 Ford F250 Light Duty: 1999.
• 5.4L V8 Ford F250 Light Duty: 1999.

You can find the underhood fuse box and relay chart for the 1997-1998 4.6L/5.4L F150 and F250 Light Duty here:

• Under Hood Fuse And Relay Box Diagram (1997-1998 F150, F250, Expedition)

More 4.6L, 5.4L Ford F150, F250, And F350 Diagnostic Tutorials

There are quite a few tutorials for the 4.6L and 5.4L equipped Ford F150, F250 pickups and Expedition SUV. You can check them out in this index:

• 4.6L, 5.4L Ford F150, F250, And F350 Index of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Clean The Ford MAF Sensor (Ford 4.2L, 4.6L, 5.4L).
• How To Test The Fuel Injectors (1997-2002 4.6L F150).
• How To Test The Ford EGR Valve EGR Vacuum Solenoid, DPFE Sensor.
• How To Test The Ford MAF Sensor (4.2L, 4.6L, 5.4L).
• How To Test The 4.6L, 5.4L Ford Throttle Position Sensor (TPS).