I have a 98 Ford ZX2. I was on the expressway today and I looked at my
speedometer to see how fast I was going, and to my surprise I wasn't moving
at all. My speedometer was at 0. When I exited the expressway and came to a
stop, my speedometer started working. Later on in the day, I got back on
the expressway and after a couple miles my speedometer thought that it was
a windshield wiper. It kept bouncing back and forth between 0 and 70.
Eventually it got tired and would only bounce between 0 and 30. My "service
engine soon" light came on and I started to get nervous. It's very wet
outside and I was driving through puddles all day. I was wondering, is it
likely that a sensor, or something connected to the computer, got wet and
caused these malfunctions? Or is it likely that something major is wrong?
Any help would be appreciated.
1. Your check engine light is on for a reason, it's trying to tell you
something. Pull codes as a starting point.
2. Yes, it may be a VSS, or... it might be a bad instrument cluster, or... it could be a combination of many things. There is a starting point for diagnostics. For that point see #1.