Taurus Speedometer problem

Hey

For some reason the speedometer in my 2000 taurus bounces to lower speed than right back up for less than a sec or two. I would be going 70 miles an hour then it will bounce back to 40 and comes right back up. I noticed it when i turn on the lights while driving it does that. Also, maybe when there are winds. I asked the mechanic he said it might be a speed sensor problem. What do you guys think ?

thanks

Ibrahim

Did you ever figure this out, my 98 has the same problem
and the shifting has problems

Have you checked for codes from the OBD-II system? From posts that I have read here I would be suspect of the VSS (Vehicle Speed Sensor). My old '94 doesn't have that so I can't speak from experience. Just what I've seen here and what I read in the Haynes manual for my '99 Windstar sugests the VSS as a prime candidate for your problems. Hope this helps. Good luck.

Thanks, is the VSS a internal or external part
do you know where it is,

thank again, jim

For the Windstar it says the VSS is located on the trans axle just above the right driveaxle. I would guess the speedometer cable should attach to the top of it. I may be wrong on this though as I have never fooled with it.