F: Speedometer/Odometer Reads Inaccurately, Ranger and Explorer: Speedometer/Odometer Reads Inaccurately, Aerostar

F1 CHECK CONNECTIONS


^ Verify connector is properly attached at speed sensor.


^ Are all connections good?


Yes


GO to F2.

No

REPAIR or REPLACE as necessary. RETEST system.



F2 CHECK ODOMETER


^ Check accuracy of odometer.


^ If odometer is accurate, calibration of speedometer may be off. Changing the speedometer may correct, but going on to change either gear will make speedometer reading more accurate, but now odometer will not be accurate.


^ Is odometer accurate?


Yes

REPLACE Speedometer. CHECK for speedometer accuracy.


No

GO to F3.



F3 CHECK DRIVEN GEAR


^ Check for proper driven gear. Refer to the Ford Speedometer Gear Supplement Charts for speedometer gear applications.


^ If odometer is accurate, calibration of speedometer may be off. Changing the speedometer may correct but going on to change either gear will make
speedometer reading more accurate, but now odometer will not be accurate.


Is the correct driven gear installed?


Yes


GO to F4.

No

REPLACE gear with correct gear. CHECK for accuracy.



F4 CHECK DRIVE GEAR AXLE, TIRES AND RATIO ADAPTOR


^ Check for proper drive gear, axle, tires and ratio adaptor.


^ Is drive gear axle, tire and ratio adapter correct?


Yes

REPLACE Speedometer. CHECK for accuracy.


No

REPLACE incorrect component or driven gear. CHECK for accuracy.