My 99 PSD speedometer quits working about once a week or so.. The overdrive button will flash on and off, also.. To fix the problem, I stopped the engine and re-start it. Works every time.. Is this a speed sensor problem? If so, where is it located? Thanks for any help..

 

VSS sensor, at the top of the rear diff, I think it's like one 10mm bolt and then just unplug and replace. Like 25 bucks if I remember right.

 

Yep, what strokedlariat said. I have a '99 also, same thing happened. Took 15min and about 15 bucks!

 

Thanks guys.. ! I will replace it today....