Thank you for the donation.
Electronic speedometers receives signals from the sepped sensors and when the signals are not as expected, it would cause the speedometer to malfunction.
That could be the reason it was stuck at 65 mph while moving. When the needle overshoots, it would not be able to return to its original resting position.
Possible causes for overshooting are either or both:
1. Current spike to the speedometer circuit. This coud mean a faulty speed sensor or its circuitry.
2. Faulty speedometer.
Here are diagnostic procedures for the speedometer. Before diagnostics, remove the meter and manually turn the needle anticlockwise to return the needle to its original resting position. If the needle cannot be returned to its position, it is faulty.
1. Raise and support vehicle. Unplug connector from vehicle speed sensor, located at transmission. Connect AC voltmeter between speed sensor terminals.
2. Start engine. Observe voltmeter. With drive wheels rotating, voltage should be 1.3-1.6 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 4).
3. Remove speed sensor from transmission. Verify presence of drive gear and clip. Inspect teeth for condition. Repair as necessary.
4. Turn ignition off. Remove instrument cluster. Inspect wires between speed sensor and instrument cluster for opens of shorts. Repair as necessary.
5. Inspect printed circuit and speedometer contact for opens or shorts between connector and speedometer. Repair or replace as necessary. If vehicle speed sensor and associated circuitry are okay, but speedometer does not operate properly, replace speedometer.
Sunday, July 4th, 2010 AT 1:31 PM