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Discussion Starter · #1 ·
Off roading on a thanksgiving trip and truck stalled after a jump. Reset intertia switch, but fuel pump is still not turning on. Engine cranks. Is there any other trick to resetting the internal switch on a 96? It stays down, but still no fuel pump hum. Going to try by passing it tomorrow morning.
 

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You might also check that there's voltage at the pump itself if the switch tests good and there's voltage at the switch.
 

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1982 Bronco XLT Lariat, 351W, C6; 1989 Bronco XLT, 302, AOD
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Look under the hood for the fuel pump relay. Press the two halves of the plug together real hard. Sometimes my truck will do this and by pressing the plug together very hard it works again. The clips that are supposed to hold the plug together are broken on my truck and the plug will separate very slightly causing a disconnect.
TB
 

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Yo Spicolli,
Welcome and congrats on acquiring the very best year Big Bronco known to men, women, children and canines!!
Section 03-04B: Fuel Charging and Controls, 5.0L and 5.8L Engines
From1996 Vehicles Equipped with 5.0L and 5.8L SFI V-8 Engines Workshop Manual​
DESCRIPTION AND OPERATION
Inertia Fuel Shutoff (IFS) Switch
The inertia fuel shutoff switch (IFS switch) (9341) is used in conjunction with an electric fuel pump. The purpose of the inertia fuel shutoff switch is to shut off the fuel pump (9350) in the event of a collision. It consists of a steel ball held in place by a magnet. When a sharp impact occurs, the ball breaks loose from the magnet, rolls up a ramp and strikes a target plate which opens the electrical contacts of the inertia fuel shutoff switch and shuts off the fuel pump. Once the inertia fuel shutoff switch is open, it must be manually reset before restarting the vehicle.

Inertia Fuel Shutoff Switch
Product Font Line Rectangle Engineering

ItemPart NumberDescription
1Electrical Contacts (Part of 9341)
2Switch Terminals (Part of 9341)
3Target Plate (Part of 9341)
4Ball (Part of 9341)
5Magnet (Part of 9341)
6Reset Button Position for Open Switch (Part of 9341)
7Closed Switch (Part of 9341)

Location pic in 92-96; "...The module I MIS-labelled as "Airbag" is actually the Wiper Control Module (WCM). The Airbag Diagnostic Module (ADM) is light blue, wrapped in black foam, above the gas pedal..."
Hood Motor vehicle Automotive tire Vehicle Automotive fuel system

Source: by absent member Fireguy50 (Ryan M)

Overview, Depiction & Wiring Diagram "...The electric fuel delivery systems differ in design and arrangement depending upon the vehicle and model year. To clarify understanding and to simplify diagnostic instruction, they are classified as either Type 1 (Single Tank) or Type 2 (Dual Tank): Type 1: Single Fuel Delivery Assembly or In-Tank Fuel Pump Assembly (Bronco) & Type 2: Dual Fuel Delivery Assembly (one assembly per tank) F Series; In order to continuously supply the fuel injectors with clean fuel at a controlled pressure, all systems require a fuel pump with a discharge check valve, a reservoir surrounding the pump inlet, a fine mesh fuel filter, a pressure regulator, a fuel supply and return system of tubes and hoses, a fuel tank, and a fuel supply manifold or fuel rail connected to the fuel injectors. The Powertrain Control Module (PCM) controls power input to the fuel delivery system and provides correct timing for the fuel injectors. The in-tank fuel pump assembly (Figure 1) has a discharge check valve (to maintain system pressure during shutdowns and to minimize starting problems), an inlet screen for protection and fuel return provision. The pump on the 3.0L Taurus FF has an additional fuel line tap used for draining the tank. The Fuel Delivery Assembly (Figure 2) consists of the fuel pump inside a reservoir that is attached to the pump and sender assembly. In a two tank system there is one assembly per tank. The sender assembly handles the switching of the fuel through internal valves. To service the assembly, replace it. The system contains four filtering or screening devices: The fuel intake sock is a screen located on the intake side of the fuel pump and is part of the fuel pump assembly. The filter screen on the fuel rail port of the injector is part of the fuel injector assembly and cannot be serviced separately. The filter screen on the fuel inlet side of the pressure regulator is part of the fuel pressure regulator assembly and cannot be serviced separately. The fuel filter assembly is located between the fuel pump and the Schrader valve or injectors. This filter should be serviced periodically by replacing it. The Shuttle Selector Valve opens the return line to the tank when the fuel pressure on the shuttle diaphragm exceeds the opposing spring force. The return flow is directed to the appropriate tank on vehicles equipped with dual tanks. The Supply Check Valve, which is normally closed, opens when the outlet pressure from the energized pump exceeds the opposing check valve spring force. When the pump is de-energized (i.e., engine is shut off), the supply check valve closes to maintain pump prime and fuel supply line pressure. A portion of the high pressure flow from the pump is diverted to operate the Venturi Jet Pump. The Venturi Pump draws fuel from the tank into the assembly. This process ensures an adequate fuel supply to the pump during extreme vehicle maneuvers and steep vehicle attitudes with low-tank fuel fill levels. The inlet of the Venturi Pump has a nylon filter on it to prevent dirt and other particulate matter from entering the system. Water in the fuel tank can pass through the filter in small quantities. When the ignition is switched to the ON position, it turns the EEC Power Relay on. The EEC Power Relay provides power to the EEIV processor and the control side of the fuel pump relay. Power for the fuel pump is supplied through a fuse link or high current fuse attached to the starter solenoid (battery side). From the fuse link or high current fuse, current flow is through the fuel pump relay and Inertia Fuel Shutoff (IFS) switch to the fuel pump. The IFS switch is a safety device used to shut off the fuel pump in the event of a collision. If the IFS switch is "tripped," it must be reset by depressing the white or red button on the top of the switch. The fuel pump relay is controlled by the Powertrain Control Module (PCM). When the ignition switch is turned to the ON position, the fuel pump will operate. If the ignition switch is not turned to the START position, the PCM will shut the fuel pump off after approximately one second. The PCM will operate the fuel pump when the ignition is in the START position to provide fuel while cranking.After the engine starts, the PCM will continue to operate the fuel pump unless the engine stops, engine speed drops below 120 rpm, or the IFS switch is "tripped." Note: Grounding the FP lead at the DLC will allow the pump to run continuously with the ignition switch on..." ●


ASAP, find out if speed control recall work, if equipped was completed. If you still have concerns about Recalls, please contact the Ford Customer Relationship Center:
US: 800-392-3673 | CA: 800-565-3673
Note: 3673 spells "FORD" on phone keys
For the hearing- or speech-impaired: Please contact the Telecommunication Relay Service by dialing 71
... have VIN ready.
"Summary: ON CERTAIN PICKUP TRUCKS, PASSENGER VEHICLES, SPORT UTILITY VEHICLES, AND MOTOR HOMES CHASSIS, THE SPEED CONTROL DEACTIVATION SWITCH MAY, UNDER CERTAIN CONDITIONS, LEAK INTERNALLY AND THEN OVERHEAT, SMOKE, OR BURN. THIS COULD RESULT IN AN UNDERHOOD FIRE."
To confirm current status, use this guide by jowens1126 @ 93 & 94-96 Cruise Control Recalls Repair
Note that the 93 recall is different than the 94-96 recall.

Here's the 1996 Bronco/F-Series Workshop Manual partial

96 Bronco Owner's Guide, Maintenance Schedules & Parts and Accessories by Ford @ Owner Manuals | fleet.ford.com

96 Bronco Dealer Brochure @ https://www.ford.com/cmslibs/conten...sovers/bronco/pdf/96_Ford_Bronco_Brochure.pdf

96 Bronco Quick Tips Brochure Excerpts & some Eddie Bauer options @ 1983 Ford Bronco 96 EB Bronco Brochures pictures, videos, and sounds | SuperMotors.net

For any Bronco questions or to chat about it's planned modifications, it's better to post each seperately in Noobie Bronco Tech Questions. Flame free zone. This will get more attention and you can build up your post count to get into other sections such as Bronco and Ford Parts/Accessories (50 posts required to participate due to scammers who preyed on our members).

See How to add your Signature @ Bronco Forum - Full Size Ford Bronco Forum by BigBlue 94

Baba Looey's Favorite FSB Links (lots and lots of tech links), includes "how do I get the tailgate glass to...", etc.

Our Sites' FAQs, includes for example:
How To Save (Bookmark) Threads Or Posts
How To Search The Site
What is the Difference Between the Showcase and Gallery?
ETC.

Try to find time to participate and vote in our current Full-Size of the Year Contest &in the ne, Full-Size of the Month Contest @ Voting
You will get ideas by those competing. Prizes are awarded to the winner; a full spread in Bronco Driver Magazine is the top prize, in addition to a years subscription, once the article is submitted; and a years worth of premium FSB membership.
Al
 

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Yo,
Had some errors here and following didnt appear:
  • Current Vehicle: 1996 Ford Bronco

HC: Fuel Delivery System

1996 PCED On Board Diagnostics II ASECTION 6A: Pinpoint Tests


  • Key off.
  • Visually inspect the complete fuel delivery system, including fuel lines, connections, pump, pressure regulator and injector areas for leaks, looseness, cracks, kinks, pinching, or abrasion caused by an accident, collision, mishandling, etc.
  • Visually inspect electrical harness and connectors for loose pins, corrosion, abrasion, or other damage from accident, mishandling, etc.
  • Verify vehicle has followed maintenance schedule.
  • Verify Inertia Fuel Shutoff (IFS) switch set.
  • Verify vehicle battery is fully charged.
  • Verify electrical/fuse integrity.
  • Verify sufficient fuel in the tank.
Has any problem been found?
YesNo
SERVICE as necessary. RERUN Quick Test.GO to HC2.
HC2 CHECK FUEL PRESSURE
  • WARNING: BEFORE SERVICING OR REPLACING ANY COMPONENTS IN THE FUEL SYSTEM, REDUCE THE POSSIBILITY OF INJURY OR FIRE BY FOLLOWING DIRECTIONS IN FUEL SYSTEM CAUTION, HANDLING ANDWARNING AT THE BEGINNING OF THIS PINPOINT TEST.
  • Key off.
  • Release the fuel pressure.
  • Install fuel pressure tester.
  • Scan Tool connected.
  • Key on, engine off.
  • Enter Output Test Mode (refer to Diagnostic Methods) and run the fuel pump to obtain maximum fuel pressure.
Is fuel pressure between 35 and 40 psi (240-280 kPa)?
YesNo
GO to HC3.GO to HC9.
HC3 CHECK FUEL PRESSURE LEAKDOWN
  • Observe Warning, Caution andNotes.
  • Fuel pressure tester installed.
  • Scan Tool connected.
  • Key on, engine off.
  • Enter Output Test Mode and run fuel pump to obtain maximum fuel pressure.
  • Exit Output Test Mode, key off.
  • Verify fuel pressure remains within 5 psi of the maximum pressure for 1 minute after turning pump off.
Does fuel pressure remain within 5 psi?
YesNo
GO to HC5.GO to HC4.
HC4 CHECK PRESSURE REGULATOR DIAPHRAGM
  • Key off.
  • Fuel pressure tester installed.
  • Start and run engine for 10 seconds.
  • Key off, wait 10 seconds.
  • Start and run engine for 10 seconds.
  • Key off, remove vacuum hose from fuel pressure regulator.
  • Inspect for fuel in the vacuum hose or regulator port.
Is vacuum hose and regulator port free of fuel?
YesNo
GO to HC11.REPLACE fuel pressure regulator. RERUN Quick Test.
HC5 CHECK FUEL PRESSURE, ENGINE RUNNING
  • Key off.
  • Fuel pressure tester installed.
  • Disconnect vacuum hose at the fuel pressure regulator and plug it.
  • Drive vehicle with heavy accelerations while observing fuel pressure gauge reading.
Does fuel pressure reading hold steady within 3 psi during test?
YesNo
UNPLUG vacuum hose and RECONNECT to the regulator. GO to HC6.GO to HC8.
HC6 CHECK FUEL PRESSURE REGULATOR RESPONSE TO VACUUM
  • Key off.
  • Fuel pressure tester installed.
  • Install vacuum gauge to intake manifold.
  • Start engine and observe both gauges.
  • Accelerate and decelerate engine speed to vary the vacuum gauge reading.
Does fuel pressure gauge reading increase as vacuum gauge reading decreases, or decrease as vacuum gauge reading increases?
YesNo
REMOVE vacuum gauge and fuel pressure tester. Problem is elsewhere. RETURN to Symptom Flowcharts, Symptom Flow Charts, for further direction.GO to HC7.
HC7 CHECK VACUUM SUPPLY
  • Key off.
  • Fuel pressure tester installed.
  • Vacuum hose disconnected and plugged at the regulator.
  • Install hand held vacuum pump to the fuel pressure regulator.
  • Start engine, run at idle.
  • Observe fuel pressure while applying vacuum.
Does the fuel pressure change as the vacuum changes?
YesNo
SERVICE vacuum system. UNPLUG vacuum hose and RECONNECT to the pressure regulator. RERUN Quick Test.REPLACE fuel pressure regulator. RERUN Quick Test.
HC8 CHECK FUEL FILTER
  • Observe Warning, Caution andHandling at the beginning of this pinpoint test.
  • Key off.
  • Scan Tool connected.
  • Replace in-line fuel filter, if not replaced recently (check maintenance log).
  • Key on, engine off.
  • Enter Output Test Mode (OTM) (refer to Diagnostic Methods) to run the fuel pump.
  • Check fuel pressure.
Is fuel pressure within specification?
YesNo
GO to HC11.GO to HC12.
HC9 CHECK REGULATOR FOR CAUSE OF HIGH PRESSURE CAUSE
  • Key off.
  • Scan Tool connected.
  • Remove fuel return line at the fuel rail and connect a short hose from rail to a measured container of at least one quart capacity.
  • Key on, engine off.
  • Enter Output Test Mode (OTM) (refer to Diagnostic Methods) and run the fuel pump.
  • Record fuel pressure and note whether fuel is being returned to the measured container.
  • Exit OTM to shut off the fuel pump, key off.
Is fuel pressure between 35 and 40 psi (240-280 kPa) and is fuel returning to the container?
YesNo
GO to HC10.Fuel Pressure greater than 45 psi (290 kPa), REPLACE Fuel Pressure Regulator. No fuel pressure, GO to HC12.
HC10 CHECK FUEL RETURN SYSTEM
  • Key off.
  • Observe Warning, Caution andHandling at the beginning of this pinpoint test.
  • Fuel line disconnected at the fuel pressure regulator.
  • Check the fuel return system for restriction due to blockage, kinking, or pinching.
  • Disconnect the fuel return line near the fuel tank.
  • Apply 3-5 psi regulated shop air to the return line at the pressure regulator side.
Does air flow freely through the line?
YesNo
REPLACE the fuel pump assembly. RERUN Quick Test.SERVICE the fuel return line. RERUN Quick Test.
HC11 CHECK FUEL INJECTOR LEAKAGE AND FLOW
  • Key off.
  • Observe Warning, Caution andHandling at the beginning of this Pinpoint Test.
  • Check injectors for leakage and flow rate, using Rotunda Injector Tester 164-R3750 and Rotunda Fuel Pump Check Valve-Pressure Regulator and Injector Leakage Tool 113-00010, SBDS Injector Tester or equivalent.
Is the flow rate for each injector within specification?
YesNo
VERIFY no other leaks. If none are found, REPLACE fuel pump assembly. RERUN Quick Test.REPLACE the defective injector. RECONNECT all components. RERUN Quick Test.
HC12 CHECK FUEL PUMP VOLTAGE
  • Key off.
  • Scan tool connected.
  • Disconnect the electrical fuel pump vehicle harness connector. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  • Key on, engine off.
  • Enter Output Test Mode and turn on the fuel pump circuit.
  • Use DVOM to check voltage to the fuel pump, at the fuel pump connector, fuel pump relay, VCRM or CCRM. (Refer to the EVTM for the specified vehicle.)
Is the voltage greater than 10.5 volts?
YesNo
CHECK for fuel pump ground connection, SERVICE as required. If OK, REPLACE fuel pump. RECONNECT all components. GO to HC2 for verification.LOCATE cause of low voltage in fuel pump circuit. SERVICE as required. GO to HC2 for verification.
 
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Discussion Starter · #6 ·
Thanks everyone. Here’s the update. Reset internal switch. Still no start with button down. Tested the switch with ignition on and not getting any voltage. Tested the fuel pump relay and not getting voltage there either. Don’t see any point testing voltage at the pump since it’s I don’t have anything at the source yet.
I read that the EEC provides power to the pump relay. Any tips on checking that circuit?
Also, the fuel pump has four wires going to it. Anyone have a description of those? Thinking worse case senario that I could disconnect the pump and run power to the pump through a separate switch to get it back home at the end of my trip?
 

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Discussion Starter · #8 ·
Bypassed inertia switch, ran pwr straight from battery to fuel pump, pump started, cranked engine, still no start. Any electrical genius ideas. This has to be computer related. Wondering if fuel injectors won’t fire if I’m bypassing the computer to power the fuel pump.
 

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Discussion Starter · #9 ·
Still stuck in the desert, but making progress. The PCM fuse is blowing out when ignition is turn on. Will spend the morning looking for the short. Have two positive to the fuse. One goes to another relay and one goes to the PCM. Both look good. Has to be somewhere that got pinched from the impact of the jump.
Also, I unplugged the PCM for one of the ignition ON tests and the fuse is still blowing, so at least I know it’s not the computer.
 

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Yo Spicolli,
Is it Maxi Fuse#9 in powertrain distribution bo
Font Material property Parallel Pattern Rectangle

Image by member Roadkill.

Possible Perpetrator is circuit 361 (Red wire), Power Output from PCM Relay. See Attached Wiring Diagrams for circuit 361.
Rectangle Schematic Font Line Slope

Rectangle Slope Font Line Parallel
Rectangle Slope Schematic Font Parallel
Rectangle Slope Schematic Font Line
Product Rectangle Slope Font Schematic

I MAY HAVE DOWNLOADED WRONG DIAGRAMS IN LAST FEW ENTRIES DUT TO FRIGGING SO CALLED "SECURITY ERRORS "
 

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Discussion Starter · #12 ·
Yes, it was the 30 amp PCM fuse. I found a bad wire on an O2 sensor that got pinch and was causing the short. Disconnected the O2 sensor and PCM is back alive. Fuel pump still isn’t working off the relay, but I’ve bypassed it for now and run pump pwr through a switch. Truck stars and runs fine so I should be able to make it home and figure the relay out when I’m back in my garage. Only a couple hour drive from where I’m at. Thanks again for the help!
 

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Yo Spicolli,
Great!
When the ignition is switched to the ON position, it turns the EEC Power Relay on. The EEC Power Relay provides power to the EEC-v processor and the control side of the fuel pump relay. Power for the fuel pump is supplied through a fusible link to the starter solenoid (battery side). From the fusible link, current flow is through the fuel pump relay and Inertia Fuel Shutoff (IFS) switch to the fuel pump. The IFS switch is a safety device used to shut off the fuel pump in the event of a collision. If the IFS switch is "tripped," it must be reset by depressing the white or red button on the top of the switch. The fuel pump relay is controlled by the Powertrain Control Module (PCM).

When the ignition switch is turned to the ON position, the fuel pump will operate. If the ignition switch is not turned to the START position, the PCM will shut the fuel pump off after approximately one second. The PCM will operate the fuel pump when the ignition is in the START position to provide fuel while cranking.

After the engine starts, the PCM will continue to operate the fuel pump unless the engine stops, engine speed drops below 120 rpm, or the IFS switch is "tripped."

If Horn HONKS, swap Horn relay into FP RELAY SOCKET
  • Shake, wiggle, bend the B(+) circuit to the fuel pump relay.
  • Lightly tap the fuel pump relay to simulate road shock.
  • Shake, wiggle, bend the Power-to-Pump circuit between the fuel pump relay and the FPM splice.
  • Key off.
  • Inspect the fuel pump relay connector for corrosion, damaged pins, etc.
 
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