Hello -
This is what our manual states for the speedometer not working..........
Looks like it could be a broken cable or it is an electronic one the sensor could be bad. I have attached the check for both until you can see which type it is.
DESCRIPTION & OPERATION
Instrument cluster includes speedometer, fuel gauge and temperature gauge. Fuel gauge has a built-in voltage limiter to keep voltage supply to gauges at 7 volts. Some models may also have a shunt-type ammeter, oil pressure gauge, tachometer, voltmeter and/or turbo boost pressure gauge. Oil pressure gauge uses full battery voltage. The tachometer operates by pulse feed.
SPEEDOMETER NOT WORKING
Ensure speedometer cable is properly connected and correctly routed. If speedometer pointer and/or odometer still do not work, replace speedometer as an assembly.
SPEED SENSOR
Voltage Test (Stealth & 3000GT With Electronic Speedometer)
Remove speed sensor from transmission. Connect speed sensor, resistor (3000-10,000 ohms) and battery. See Fig. 32 . Using a voltmeter, ensure voltage pulses on and off 4 times per revolution of speedometer shaft. Replace sensor if voltage is not as specified.

Oct 11, 2009 at 10:30 PM