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faulty scorpio speedo
Your battery is not charging. It is either due to a faulty battery or a faulty alternator. Get it changed.
On a high energy ignition, possible problems include: Faulty keyswitch, faulty wiring or connectors, faulty pickup inside the distributor, faulty electrical condenser, if it has points (depends on the type of HEI) the points could be bad, faulty coil or faulty HEI control module. You will need to identify which component has failed.
fault starter/cable, faulty solenoid, faulty wiring harness, or undercharged battery.
Your computer or Module is faulty.
If it is a cable driven system, usually a jerky needle is caused by a dry cable, either replace or lube the cable as it is getting stuck and stopping for a second then getting unstuck and jumping back to current speed. If it is an electronic speedo then it could be a loose connection under the car, usually they tie into the transmission to get speed input. Or could be as worse as a faulty speedo in the dash.
You need to determine if it's the speedometer itself that's faulty, or the vehicle speed sensor. If the speedometer is faulty, you'll need to replace the instrument cluster.
I'm not 100% certain, but I believe that model year still uses a mechanical speedometer, in which case, it's likely either your speedometer cable or faulty gears in the speedometer itself. If it is electronic - which is possible, as again I'm not 100% certain that the 95 uses a mechanical speedometer - and the rest of your gauges are working, there'll be a speed sensor on the transmission with an electrical pigtail running to it... faulty sensors or faulty wiring are the probable causes.
Its either a faulty cable or a faulty electrical connection.
faulty circut board replace it
Could be a faulty sensor
Faulty vehicle speed sensor.
Does your odometer work? If the speed sensor goes faulty both speedometer and odometer stop working.
Could be a loose cable (connection on the back of the speedometer). In today's electronics on cars it's best to take it to a mechanic who knows what they are doing for the repair. You might want to save the money, but if you mess something else up trying to fix the one thing it might cost you even more.
You would fix it by replacing the instrument cluster. The speedometer itself may not be faulty, it is more likely to be a problem with the speed sensor.
When the speedometer stops working and the ABS or traction disabled light comes on in a vehicle it indicates that the vehicle's ABS system is faulty. This could be indicative of a faulty wheel sensor or the ABS tracking system itself.
A faulty vss (vehicle speed sensor).
You have a faulty gearbox.