Speedometer Reads "O" With Vehicle In Motion

If speedometer reads "188" when ignition switch is first turned "ON", proceed to step 2). If "188" not displayed, replace speedometer electronics assembly.
If odometer advances when vehicle is moved forward, proceed to step 3). If odometer does not advance, proceed to step 4).
Inspect speedometer. Verify that optoelectronic sensor is attached to bridge and engaged in disc encoder. If okay, replace speedometer electronics assembly. If not okay, secure optoelectronic sensor to bridge at disc encoder.
Check speedometer cable-to-head connection. If connection okay, proceed to step 5). If connection not okay, service connection and cable as necessary.
Disconnect cable at speedometer and check core for rotation when driveshaft is rotated. If core rotates, proceed to step 6). If core does not rotate, proceed to step 7).
Inspect core tip for broken or damaged condition. If tip is okay, remove speedometer and inspect gear train. If damaged, replace speedometer head. If tip is broken or damaged, replace cable core.
Inspect core for broken or damaged condition. If core okay, proceed to step 8). If core damaged or broken, replace core.
Disconnect cable from transmission. Inspect driven gear teeth for wear. Check retainer clip for position and condition. If okay, proceed to step 9). If not okay, replace damaged gear and retainer clip.
Verify presence of drive gear on transmission output shaft. If drive gear okay and present, replace cable. If drive gear damaged or missing, service or replace gear as necessary.