Questions and Answers
Ford Mustang Speedometer Drops
Q. Hi Vince! First of all, You're STILL DA' MAN when it comes to car repair!! You've been helping me with this 1994 Ford Mustang GT, 5.0 liter HO, 174,000 miles, EFI, ABS, P/S and A/C since 1998. My "Future Classic." The speedometer needle dropped to zero while cruising at 35 mph. I then accelerated and it came around, back to the normal calibration, I hope.
It sporadically drops to zero, but it comes back shortly. What is it? Is that a cable run from the dashboard to the front wheel, like the old days, or is there a sensor somewhere else? Let me know.
Thanks!!
MitchA.
Sounds to me like a bad Vehicle Speed Sensor (VSS) or a bad electrical connection. To check it you can raise the drive wheels off the ground. Then connect an AC voltmeter to the output pins and start the car. The voltage should be between 1.3 to 6.1 volts AC. If it is, it's okay.If it is okay, then you probably have a bad speedometer head.
![]()
Additional Information provided courtesy of AllDATA

