'93 5.8 Bronco No Start

amk

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Hi All - I am dealing with a no start condition on my Bronco and am looking for some diagnostic tips. This is an old, rusty truck and I don't have knowledge of its maintenance.

I have what started as a no fuel, no spark issue: confirmed with a spark plug tester at the plug wires and coil wire, as well as a fuel pressure gauge. Nothing. About a month ago, the truck would crank.

Now, it won't even crank unless I jump the solenoid. Jumping will crank the engine, but there is still no fuel or spark

Turning key to RUN position does not prime fuel pump. The only dash lights I see are the 1) airbag light, 2) ABS and 3) Brake light. No CEL.
Turning key to START position - I hear a relay click but nothing else. I've tried a few good 12+ volt batteries.

Any suggestions on what to look for?
 

Tiha

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Fuses and relays, I would swap them all around first. Check all of the fuses. Move relays around see if anything changes.

ECM may not be getting power but that is not the same as not cranking.

Could be simple ignition switch.
 

amk

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Thanks - I checked all fuses and switched around the EEC, Fuel pump and horn relays. I can get the fuel pump to run when I jump the fuel pump relay or trigger it through the test socket. I also removed the ignition switch under the steering column and have tried all three key positions (ACC, Run, Start) from that device with no change
 

amk

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I have read a lot about the EEC / ECU going bad but am not aware of a way to test whether that may be the case. Is there a way to confirm whether the ECU is receiving power?
 
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miesk5

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Yo AMK,
WELCOME!
Does your 93 have anti-theft system?
Anti-Theft Overview in 92-96 in E-150-250-350 Vehicles; "...The anti-theft protection system provides two types of vehicle protection. The first is designed to provide the vehicle with protection from unauthorized entry into the passenger compartment and engine compartment (hood opening). The second monitors the status of the ignition switch lock cylinder. If triggered, the system provides both audio and visual alarm signals and disables the starter circuit. The system is controlled by an electronic module. When armed, unauthorized entry into the vehicle is detected by courtesy lamp switches (located in the passenger compartment door jambs), and a hood switch (located on the right cowl surface). In addition, the system triggers an alarm if the ignition switch lock cylinder is forcibly removed from the steering column tube (3514). The system immediately monitors the ignition switch lock cylinder upon removal of the key from the ignition. Once triggered, the system flashes the low beam headlamps, the parking lamps, the alarm indicator, and sounds the horn. In addition, the starter circuit is interrupted until the system is disarmed..." by Ford


  • Starter Motor Does Not Crank Engine
  • Loose or corroded battery cable connections.
  • Undercharged battery.
  • Malfunctioning starter relay.
  • Faulty starter motor ground circuit.
  • Malfunctioning starter motor.
  • Malfunctioning ignition/push-button switch.

Following by Ford with additions by the usual suspects;

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Item Part Number Description
1 3F532 Key Release Lever Spring
2 11572 Ignition Switch
3 7210 Gearshift Lever
4 7A247 Park/Neutral Position Switch or
5 11A152 Clutch Pedal Position Switch
6 11450 Starter Motor Relay
7 11001 Starter Motor
8 11390 Starter Solenoid
9 10655 Battery
B1 check the battery voltage, terminals and cables to ground & alternator for loose or corroded connections.

Voltage; "...a normal battery that is fully charged produces 12.6 volts, not just 12.0 V. (Remember, when measuring battery voltage, everything in the car should be off, or the battery should be disconnected. Voltage measurements are always "no load" measurements unless the battery is being tested for it's performance under load)..." by Gordon

Ground Location,
Frame from Battery pic in a 94 5.8;
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"...Frame ground just inboard of the R spring tower. The black battery wire goes from the front bolt of the engine mount (on the block) to this tab & up to the battery post, where a smaller black wire goes to the core support, providing a continuous ground path between the engine, frame, battery, & body..."

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Source: by CodysBigBlueBronco (how much $???)

Frame Ground location (Passenger side Cross member above
engine mount)
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by jowens1126

Intake Manifold to Block ******** oassenger side Location pic in a 96 5. by bossind
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Inspect STARTER RELAY GROUND; relay located on PASSENGER FENDER LINER, near battery, see Starter Relay pic in a 95
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Source: by Shane C. (BigBlue, bigbluebronk)
Check for continuity between relay mounting bracket and clean chassis ground. Rust, grime, paint etc interferes with relay control circuit.
B3 STARTER RELAY FUNCTION
CAUTION: Make sure transmission is in neutral and parking brake is applied.
Connect remote starter switch between battery terminal at starter relay and starter relay S terminal.
Press remote starter switch button or jump it.
Does starter crank engine?
Yes If equipped with an automatic transmission, GO to B4. If equipped with a manual transmission, GO to B7. If relay does not click, GO to B9.
If relay clicks, GO to B10.

B4 With key in START position, check for battery voltage at starter relay S terminal (R/BL). It is the smallest terminal on the relay and the R/BL wire has a push on/pull off connector.

Is battery voltage present?
Yes GO to B9.
NO GO to B5.

B5 BATTERY FEED FROM TRANSMISSION RANGE (TR) SENSOR
With key in START position, check for battery voltage at TR sensor terminal (R/LB).
Is voltage present?
Yes REPAIR open in Circuit 32 (R/LB) between relay and sensor/switch.
NO GO to B6.

B6 BATTERY FEED TO TRANSMISSION RANGE (TR) SENSOR, aka Manual Lever Position Sensor/Transmission Range (TR) Sensor
See pics by jermil01 @ 1992 Ford Bronco MLPS pictures, videos, and sounds | SuperMotors.net
With key in START position, check for battery voltage at TR sensor terminal (W/PK).
Is voltage present?
Yes CHECK TR sensor switch adjustment. REFER to below note 1
REPLACE sensor/switch, if properly adjjusted
NO REPAIR open in circuit between sensor/switch and starter relay.

B7 BATTERY FEED TO CLUTCH PEDAL POSITION SWITCH
With key in START position, check for battery voltage at CPP switch terminal (R/LB).
Is voltage present?
Yes GO to B8.
No REPAIR open in circuit between ignition switch and CPP switch.

B8 CLUTCH PEDAL POSITION (CPP) SWITCH CONTINUITY
With key in START position and clutch pedal pressed, check for battery voltage at CPP switch terminal (W/PK).
Is voltage present?
Yes REPAIR open in circuit between CPP switch and starter relay.
No REPLACE CPP switch.

B9 STARTER RELAY GROUND
Check for continuity between relay mounting bracket and clean chassis ground.
Is there continuity?
Yes REPLACE starter relay.
No CLEAN ground connection.

B10 BATTERY FEED TO STARTER SOLENOID ATOP STARTER, NOT THE RELAY ON PASSENGER FENDER LINER:
With key/push-button switch in start position, check for battery voltage at starter solenoid S terminal (R/BL).
Is battery voltage present?
Yes GO to B11.
No REPAIR open in Circuit 32 (R/BL) between relay and solenoid.

B11 STARTER SOLENOID ATOP STARTER, NOT THE RELAY ON PASSENGER FENDER LINER:
Check starter solenoid: inspect wire &;
Starter Solenoid
Disconnect battery negative cable.
Using a Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent, check windings of solenoid assembly for continuity as follows:
Check resistance of solenoid pull-in and hold-in windings in series by measuring resistance between motor terminal and solenoid case. Resistance should be approximately 0.95 ohms.

An extremely high resistance reading indicates a break or fault in winding continuity. A very low resistance reading indicates a short or ground in the winding circuit. Either condition is cause for replacement of the solenoid assembly.
Is starter solenoid OK?
Yes REMOVE starter and perform no-load test at parts store.
No REPLACE starter solenoid.
°

Note 1 Transmission Range (TR) Sensor
SPECIAL SERVICE TOOL(S) REQUIRED
Description Tool Number
Transmission Range (TR) Sensor (MLPS) Alignment Tool T92P-70010-AH
Remove nut securing manual control lever (7A256) to transmission range (TR) sensor.
Turn manual control lever to NEUTRAL position.
Loosen two TR sensor retaining bolts.
Align TR sensor slots using Transmission Range (TR) Sensor (MLPS) Alignment Tool T92P-70010-AH.
Tighten retaining bolts to 6-8 Nm (55-75 lb-in) for E40D and to 7-10 Nm (62-89 lb-in) for 4R70W.
Install nut retaining manual control lever to TR sensor. Tighten to 27-38 Nm (20-29 lb-ft) for E4OD and to 30-35 Nm (22-26 lb-ft) for 4R70W.
Or, as bigric wrote, "...You don't need a tool. Just put it in neutral, loosen the bolts, and line up the marks."

Or, Adjustment Info; "...back-probe the MLP line with a volt meter while in Park, and set it to between 4.277 and 4.736 volts (ideally at 4.5065V, right in the middle of the two limits). As a "double-check" afterward, pull the lever down to 1st gear, and again test the MLP voltage; it should be between 0.293 and 1.167 volts, ideally in the middle at 0.73V..."
Source: by SigEpBlue (Steve) at FSB

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Pic by ElKabong

"STARTER MOTOR SPINS BUT DOESN'T CRANK ENGINE:
Check Starter drive engagement & flywheel.
Inspect flywheel and drive pinion for damage or excessive wear. See image.
Check operation of drive pinion overrunning clutch;
UNUSUAL STARTER MOTOR NOISE DURING STARTER MOTOR OVERRUN

D1 CHECK STARTER MOTOR MOUNTING
Inspect the starter motor mounting.
Check the starter motor mounting bolts for looseness.
Is the starter motor mounted properly?
Yes GO to D2. No REMOUNT or REPLACE the starter motor.

D2 CHECK STARTER DRIVE ENGAGEMENT
Remove the starter motor.
Inspect the starter drive and flywheel for damage. REFER to Pinpoint Test C1.
Are the starter drive and flywheel OK?
Yes CHECK drive pinion overrunning clutch. REFER to Component Tests in the Diagnosis and Testing portion of this section.
No REPLACE as necessary."
 

miesk5

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Part 2 due to dumb assed character number restiction.
Ignition Switch Mechanical Test
NOTE: Accessories that fail to operate with the key in RUN, or that remain on when the key is turned off, may be the result of a misadjusted ignition switch rather than a malfunctioning ignition switch.

NOTE: Do not apply lubricant to the inside of the ignition switch.
Test the steering column ignition system mechanical operation by rotating the ignition switch lock cylinder (11582) through all positions of the ignition switch. The movement should feel smooth with no sticking or binding. The ignition system should return from the START position back to the ON position without assistance (spring return). If sticking or binding is encountered, check for the following:
Loose column
burrs on the ignition switch lock cylinder
binding ignition switch lock cylinder
shroud rubbing against ignition switch lock cylinder
burrs or foreign material around the rack-and-pinion actuator in the housing of the ignition switch lock cylinder
insufficient **** on actuator
binding ignition switch.


Sixlitre described a no crank issue that involved the actuator rod issue in a tilt column, but applicable to non-tilt; "...He turned the key on to crank (nothing happened), reached low on the column, just below the dash, and shoved his pick tool into the column and pulled down. That thing not only rolled over but it started...SO IN CONCLUSION REACH UNDER YOUR DASH AND PULL DOWN ON THAT COLUMN SWITCH ACTUATOR ROD (with the key on) AND SHE'LL LIKELY START RIGHT UP. He told me yes the switches die but they can also "walk" up the column and and get so loose the rod coming down from the key will not actuate the column switch (it's also a sign the $11 switch is about to die). He also recommended I change that *** metal actuator rod assembly (Ford # E9TZ*3E715*B, $16.32 CDN). This took him half an hour and if I'd been able to do it I estimate even after my install lesson would have taken me most of the day..."
Source: by Sixlitre (Malcolm H, Eddie Bauer) at FSB
I won't suggest that you try to manually manipulate actuator if starter rotates with key off because of possible damage to: starter, pinion, flywheel etc. But you can disconnect battery, hook up a meter or 12vdc test lamp and test for continuity on the red/light blue wire Circuit.

See cranks, but No Start @ Part 1 -How to Troubleshoot a No Start (Ford 4.9L, 5.0L, 5.8L).
First, grab spark tester, fuel pressure test kit, etc at local parts store with refundable deposit.

To be continued
 

miesk5

96 Bronco 5.0
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Yo AMK,
If you can't get a code reader to hook up while the key is in the run position (doesn't matter if engine is running or not) then you're dealing with a EEC,
OR a ground or wiring problem.
Or possible loss of power fuse/relay.
If the EEC IV's RAM has failed, the check engine light will light and no codes are output.


The ICM can fire the spark plugs independently without EEC control but the fuel injectors will never fire if the EEC isn't working/operational. Have a buddy put his finger on one of the injectors while cranking the engine. You should feel them pulse if everything is working on the EEC side.

Common PCM Failure Symptoms
it could be sending the signal to the fuel pump relay to turn the fuel pumps on; One easy test for this is: without the key in ignition, bump the starter over @ the starter relay using a screwdriver. If it is the EEC relay, the truck will start without the key in the ignition..."
Source: by sackman9975

OR, the fuel pump runs continuously when key is in the on position and engine is off.
With No Codes;
Starts, but doesn't run;
an improperly-balanced fuel-to-air ratio
timing is off

Sudden Loss of Gas Mileage.
Failed Emissions Test but no codes. (See below)
Engine Stutters or Stalls.
Erratic or Random Shifting.
You're Receiving a PCM-Related Error Code.

No Codes? By Ryan M
The famous No Code situation that people describe usually ends up being user error. Not that I blame anyone for not getting codes, but the Ford computer outlasts everything else on a vehicle from bumper to bumper. So PLEASE read how to perform a Self-Test and getting Trouble-Codes before tearing the vehicle apart. Replacing computers more than once on a vehicle is not an acceptable repair, other problems exist in that vehicle. Most No Code situations are caused by wiring problems. I have created a list of things to check. Hopefully you can get this sorted out with out burning up computers or beating your head against a wall.
•Check Battery voltage, must be above 10.5 volts.
•Replace battery if not.
•Check battery connections, corrosion, ground faults, and wiring.
• Fix all wiring.
•Check alternator output, must be between 13.5 and 14.5 volts.
•Replace Alternator if not.
•Any recent voltage irregularities from electrical charging system can cause failures.
•Replace alternator and any damaged circuits, wiring, and components.
•Check fusible links on Starter Solenoid if equipped.
•Check fuses and surge protection diode in under hood Power Distribution Box.
•Replace any fuses, diodes, and links if needed.
•Check EEC relay, must show battery voltage when engaged.
•Replace relay and damaged wiring if not.
•Make sure pin 30 on the computer is hooked up correctly.
•Manual transmission computers need to sense SIG-RTN on pin 30 when in neutral.
•Automatic transmission computers need to sense Ground on pin 30 when in neutral.
•Electronicly controled automatic computers need an operational Manual Lever Position Sensor (MLPS)
•Check aftermarket devices like alarm system connected to engine or computer components.
•Restore engine and computer system to original configuration.
•Check aftermarket computer chips and other plug in controls.
•Any chips or controls that impede basic engine and computer function need to be removed.
•Restore computer and harness to original configuration.
•Disconnect computer and inspect for damaged or pushed out pins, corrosion, loose wires.
•Replace computer if visually damaged, repair any damaged pins in harness.
•Visually inspect the ENTIRE engine and computer wiring harness and connections for corrosion, ground faults, shorts, physical damage, and general condition.
•FIX ANY & ALL PROBLEMS!
•Check Self-Test Input circuit on Pin 48 at computer harness for shorts to ground."

Here are some PCM KILLER perpetrators and other causes:
Smell around the PCM. If it smells like dead fish, it's bad.
Look for PCM printed circuit board burn marks around leaking capacitors, resistors.
For example, see Old leaky capacitors in swapped EEC and no more codes by jowens1126
Water damage from cowl leaks, ESPECIALLY if you you have wet carpet or mat near driver kick panel; or on PCM Connector due to a bad hood seal near cowl panel, viewable with hood up.
Corrosion or damage due to moisture is one of the main reasons for failure. Corrosion can enter through the wiring harness and moisture can enter by a failure in the seals in the PCM itself. This happens over a period of time (5 to 10 years) due to exposure to the elements.
The alternator could be generating an AC voltage spike due to bad diode(s) or supply Voltage Overloads.
I recommend bench-testing the alternator for voltage output and AC voltage ripple.
Thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail.
Bronco was jump started on reverse polarity.
Connector pin damage or corrosion,
Other Internals:
broken tracks,
cold solder joints,
short circuit,
thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail,
Bad Intel 8061 chip or bad Intel 8361 memory chip,
Bad Internal Voltage Regulator, see Wayback Machine by Fireguy50 (Ryan M)

Find out if speed control, if equipped, recall work completed.
If you still have concerns about Recalls, please contact the 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 711.
... 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."
See this guide by jowens1126 to confirm recall status @ 93 & 94-96 Cruise Control Recalls Repair
Note that the 93 recall is different than 94-96.

Here is the 1993 Bronco Dealer Brochure in Google Drive @ 93Bronco.pdf

1993 Bronco Dealer Training Video via silver70 @
xc_hide_links_from_guests_guests_error_hide_media

1993 Bronco, Venezuela Commercial @
xc_hide_links_from_guests_guests_error_hide_media

Haynes Red Manual for 80-95 Bronco & F Series @ Hanes guide 80-96 bko f series.pdf via BroncMom
 

Popoagie6

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Part 2 due to dumb assed character number restiction.
Ignition Switch Mechanical Test
NOTE: Accessories that fail to operate with the key in RUN, or that remain on when the key is turned off, may be the result of a misadjusted ignition switch rather than a malfunctioning ignition switch.

NOTE: Do not apply lubricant to the inside of the ignition switch.
Test the steering column ignition system mechanical operation by rotating the ignition switch lock cylinder (11582) through all positions of the ignition switch. The movement should feel smooth with no sticking or binding. The ignition system should return from the START position back to the ON position without assistance (spring return). If sticking or binding is encountered, check for the following:
Loose column
burrs on the ignition switch lock cylinder
binding ignition switch lock cylinder
shroud rubbing against ignition switch lock cylinder
burrs or foreign material around the rack-and-pinion actuator in the housing of the ignition switch lock cylinder
insufficient **** on actuator
binding ignition switch.


Sixlitre described a no crank issue that involved the actuator rod issue in a tilt column, but applicable to non-tilt; "...He turned the key on to crank (nothing happened), reached low on the column, just below the dash, and shoved his pick tool into the column and pulled down. That thing not only rolled over but it started...SO IN CONCLUSION REACH UNDER YOUR DASH AND PULL DOWN ON THAT COLUMN SWITCH ACTUATOR ROD (with the key on) AND SHE'LL LIKELY START RIGHT UP. He told me yes the switches die but they can also "walk" up the column and and get so loose the rod coming down from the key will not actuate the column switch (it's also a sign the $11 switch is about to die). He also recommended I change that *** metal actuator rod assembly (Ford # E9TZ*3E715*B, $16.32 CDN). This took him half an hour and if I'd been able to do it I estimate even after my install lesson would have taken me most of the day..."
Source: by Sixlitre (Malcolm H, Eddie Bauer) at FSB"
I won't suggest that you try to manually manipulate actuator if starter rotates with key off because of possible damage to: starter, pinion, flywheel etc. But you can disconnect battery, hook up a meter or 12vdc test lamp and test for continuity on the red/light blue wire Circuit.

See cranks, but No Start @ Part 1 -How to Troubleshoot a No Start (Ford 4.9L, 5.0L, 5.8L).
First, grab spark tester, fuel pressure test kit, etc at local parts store with refundable deposit.

To be continued
As a technical writer and teacher, I love this. Also, I concur with "Part 2 due to dumb assed character number restriction." Why must we be restricted to so few characters? The world needs more characters, right?
 

miesk5

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As a technical writer and teacher, I love this. Also, I concur with "Part 2 due to dumb assed character number restriction." Why must we be restricted to so few characters? The world needs more characters, right?
Yo Pop,
Someone decided to impose limits in order to justify their salary.
Why not limit it to 10,006?
Oh! I know why...
The number is a favorite of somene else who demands more $! 🥨
Be well Pop!
 

amk

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Thank you for this - I will start working through these tests and report back!!!!
 

Black Bronco King

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Hi All - I am dealing with a no start condition on my Bronco and am looking for some diagnostic tips. This is an old, rusty truck and I don't have knowledge of its maintenance.

I have what started as a no fuel, no spark issue: confirmed with a spark plug tester at the plug wires and coil wire, as well as a fuel pressure gauge. Nothing. About a month ago, the truck would crank.

Now, it won't even crank unless I jump the solenoid. Jumping will crank the engine, but there is still no fuel or spark

Turning key to RUN position does not prime fuel pump. The only dash lights I see are the 1) airbag light, 2) ABS and 3) Brake light. No CEL.
Turning key to START position - I hear a relay click but nothing else. I've tried a few good 12+ volt batteries.

Any suggestions on what to look for?
Fords are notorious (as my '94 was) for having BAD starter solenoids. They are located on the passenger side wheel well. I banged on it good and hard and danged if it didn't release and start right up. They freeze up somehow. Went and bought an OEM replacement and it's worked well since. Hope this is helpful.
 

amk

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Thanks, I have confirmed it's not the solenoid - no 12v signal coming to it when I turn the ignition. I have done as much troubleshooting as I can figure out how to do and have ordered a new EEC. Hopefully it's here in a few days and I will report back. I have no signs of life when I turn the key, except the ABS system. No fuel pump prime, no fuel pressure, no spark. Nothing happens. Relays all seemed to be fine as well.

I also bypassed the whole ignition/key cylinder assembly and just moved the actuator under the dash - no effect.
 

Tiha

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Before you install that ECM and can't return it, did you check for voltage at the ignition switch? I think there should be like 2 wires that are hot all the time. One of them being a bigger wire than the rest.

Do things like the winshield wipers work? Power windows? Blower motor? Radio?
 

amk

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Yes, all of that stuff works fine with key / ignition switch in ON position. But, no fuel pump prime. The fuel pump does run when you jump the relay.
 

amk

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Just wanted to report back: I received the new EEC and the truck started up right away. Thank you all for the suggestions!
 

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