Operation CHARM: Car repair manuals for everyone.

Speed Control/Speedometer


1980-87 Models Exc. 1983-87 Ranger, 1984-87 Bronco II & 1986-87 Aerostar
1. Disconnect 6 way connector from amplifier assembly, then connect an ohmmeter between dark green wire w/white stripe and black wire on 1980 E-100-350, 1981-83 F-100-350 models and Bronco, and 1984-87 F-150-350 and Bronco, or green and black wire on 1980 F-100-350 and 1981-83 E-100-350 models and 1984-87 E-150-350 at the speed sensor end. A reading of 40 ohms should be obtained. A reading of 0 ohms indicates a shorted coil and an infinity reading indicates an open coil.
2. Replace sensor if a correct reading has not been obtained.



1983-87 Ranger, 1984-87 Bronco II & 1986-87 Aerostar
1. Disconnect speed sensor connector, then connect an ohmmeter between dark green wire with white stripe and black wires.
2. A reading of 180-250 ohms should be obtained. A reading of 0 ohms indicates a shorted coil and an infinity reading indicates an open coil.
3. Replace sensor if a proper reading has not been obtained.