Warning Indicators

Brake System

All vehicles use a brake warning light in the instrument cluster (10849) to warn of system malfunctions. The red warning light for the brakes can indicate three conditions:

• the parking brake is not fully released
• the brake fluid level is low in the master cylinder reservoir
• the vacuum pressure is low on diesel engine vehicles

Anti-Lock Brakes, Bronco

The anti-lock brake system uses one amber ABS warning light to alert the driver of malfunctions in the system.

The amber ABS warning light will come on for numerous reasons. It warns the driver that the ABS has been disabled. Normal power-assisted braking remains but the wheels can lock during a panic stop while the indicator is on. Certain procedures must be followed to find the concern in this situation. Refer to Section 06-09B for diagnosis and testing of the system.

Rear Anti-Lock Brakes, F-Series

The yellow anti-lock brake indicator lights up for approximately two seconds when the key is first moved to RUN or START for circuit proveout. The indicator also lights up when the RABS module detects a malfunction in the system.

The self-test feature contains codes that indicate the area of the malfunction. When a malfunction is detected, the RABS control module shuts down the system and the yellow anti-lock warning indicator comes on. This permits normal braking. A code can be retrieved by momentarily grounding the diagnostic pigtail (black with orange stripe wire) after it is disconnected from KAM (keep-alive power red wire) and counting the flashes of the yellow ABS lamp. To make sure the diagnostic trouble code (DTC) is not lost from memory, the key must be left in the RUN position before the diagnostic lead is disconnected from KAM power. If more than one diagnostic trouble code exists, only the first code stored will be displayed. Additional codes will be output only after the first fault is corrected.

Check Engine (MIL)

The check engine warning indicator comes on when the electronic engine control system is not working properly.

The CHECK ENGINE warning indicator comes on briefly when the key is turned to RUN, and should turn off when the engine (6007) starts. If the CHECK ENGINE warning indicator does not come on when the key is turned to RUN or if it comes on while the vehicle is moving, the system is malfunctioning.

NOTE: If the vehicle is equipped with dual fuel tanks (9002), the CHECK ENGINE light may come on if fuel is restricted to the engine or if the fuel flow is momentarily disrupted because of an empty fuel tank before switching to the auxiliary fuel tank. This condition is normal and the CHECK ENGINE light should go off sometime after fuel flow is restored.

Charging System

The charge indicator lights if the voltage in the integral generator drops below a preset level while the key is in RUN.

The charge indicator light comes on every time the key is turned to RUN or START. The light should go off when the engine starts and the generator (GEN) (10346) begins to charge.

Air Bag (if Equipped)

The air bag warning indicator will illuminate for six seconds when the key is turned to the RUN position. If the air bag warning indicator fails to illuminate, continues to flash, remains on, or if a series of five beeps is heard, the system requires service.

Safety Belt

The safety belt warning light reminds the driver to fasten safety belt. Each time the key is turned to RUN, the warning light will come on for a short time to remind the driver to fasten the safety belt.

High Beam

The high beam indicator comes on when the headlamps are turned on high beam or when the headlamps are flashed, and indicates that the headlights are illuminated at reduced intensity for daytime running lamps.

LH/RH Turn

The LH/RH turn signal indicators are located in the instrument cluster. If the turn signal indicator light in the instrument cluster does not illuminate or remains on (does not flash) when a turn is signaled, the turn signaling system is malfunctioning.

Overdrive/Overdrive Off

The OVERDRIVE OFF indicator lights when the transmission is locked out of OVERDRIVE. This is done by pressing the switch button in the end of the gear selector lever.

Heated Back Window Light, Bronco

The heated back window switch has a push button spring-loaded to neutral position to turn the system on or off. A timer-controlled relay illuminates the switch for approximately 10 minutes of operation.

Electronic 4-Wheel Drive

A 4x4 indicator light and a LOW RANGE indicator light are located at the lower right of the instrument cluster. In addition, two small amber lights are located near the Touch Drive buttons. The amber light to the left of the 4x4 button will light up at the same time as the 4x4 instrument cluster light. The amber light to the left of the LOW RANGE light will light up at the same time as the instrument cluster LOW RANGE light.

4x4 High Range

When the 4-wheel drive high range is engaged, the switch closes at first contact and the 4x4 HIGH RANGE lamp illuminates. When the low range is engaged, the switch closes a second contact and the low range bulb illuminates at the same time as the 4x4 LOW RANGE lamp illuminates.

4x4 Low Range

The 4x4 low and high lamp circuit consists of two indicator lamps located on the instrument cluster and a switch located in the transfer case. One lamp indicates when the vehicle is in the 4-wheel drive high range position (4H) and one lamp indicates when the vehicle is in the 4-wheel drive position (4L).

Fuel Filter, 7.3L Diesel

The 7.3L diesel engine is equipped with a fuel filter restriction sensor. A restriction indicator light is provided on the instrument panel (04320) warning lamp module to alert the operator.

If the restriction indicator light goes on during normal operation, the fuel filter should be changed as soon as practical.

Water in Fuel, 7.3L Diesel

During refueling it is possible for water-contaminated diesel fuel to be pumped into the fuel tank. The 7.3L diesel fuel system is equipped with a fuel filter/heater/water separator to remove water from the fuel. The WATER IN FUEL light in the warning lamp module will glow when the fuel filter/heater/water separator has a significant quantity of water, or when the key is switched to the START position (light function check). If the light glows red while the engine is running, the engine should be stopped as soon as safely possible, the engine shut off and the fuel filter/water separator drained.

 WARNING: DO NOT DRAIN WATER SEPARATOR WHILE ENGINE IS RUNNING. FUEL MAY IGNITE IF SEPARATOR IS DRAINED WHILE ENGINE IS RUNNING OR VEHICLE IS MOVING. REFER TO OWNER GUIDE BOOKLET FOR WATER SEPARATOR DRAIN PROCEDURES.

 CAUTION: Allowing water to stay in the fuel system could result in extensive damage to, or failure of, the fuel injection system.

Fuel Reset

If the engine cranks but does not start or does not start after a collision, the inertia fuel shutoff switch (IFS switch) (9341) may be triggered. The inertia fuel shutoff switch is a device intended to automatically stop the flow of fuel to the engine when the vehicle has been involved in a collision. The impact does not have to be great for the inertia fuel shutoff switch to be triggered. Minor parking lot bumping and severe road impacts (such as potholes) may trigger the inertia fuel shutoff switch even when there is no apparent body damage.

 WARNING: IF YOU SEE OR SMELL FUEL, DO NOT RESET THE INERTIA FUEL SHUTOFF SWITCH OR TRY TO START THE VEHICLE. YOU COULD INJURE YOURSELF OR OTHERS. HAVE ALL PASSENGERS GET OUT OF THE VEHICLE AND CALL THE LOCAL FIRE DEPARTMENT OR A TOWING SERVICE.

Once the inertia fuel shutoff switch is triggered, the switch must be reset by hand before the vehicle can be started. Refer to the Owner Guide for further information.

Wait To Start, 7.3L Diesel

With the key in the RUN position, the WAIT TO START indicator will light within the diesel warning lamp module if glow plug heat is necessary as a starting aid. The operator should wait until the light goes off before starting. If the indicator does not light, the engine may be started immediately. Refer to the Owner Guide for further information. After the engine starts, the indicator light will turn off.

The WAIT TO START light should always come on at least momentarily when the engine is cold and the key is first switched to RUN. If it does not, the glow plug system should be checked and repaired promptly to avoid difficult cold starting.