Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

1987 Ford Econoline E350, Van Window, 7.5 LFACTORY OEM SERVICE PROCEDURE

Wiring Harness

Disconnect wiring harness connector from ignition module. Inspect connector for dirt, corrosion or damage. Disconnect wire at "S" terminal of starter solenoid.

Attach negative voltmeter lead to distributor base. Measure battery voltage. With negative lead of voltmeter still connected to distributor base, check voltages at TFI-IV ignition module wiring harness terminals. See Fig 1. See WIRING HARNESS TEST table.

WIRING HARNESS TEST

Connector Terminal No.	Wire (Circuit)	Ignition Switch Test Position
2	Coil-Terminal	"RUN"
3	Run	"RUN" or "START"
4	Start	"Start"

If all readings are at least 90% of battery voltage, wiring harness and connectors are okay. Go to STATOR test. If reading is less than 90% of battery voltage, inspect wiring harness and connectors. Also check for a worn or damaged ignition switch. Repair or replace as necessary. Turn ignition off. Remove voltmeter. Connect "S" terminal to starter solenoid.

Fig 1: Wiring Harness Test

Courtesy of FORD MOTOR CO.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

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