I've got a 2000 Ranger 4x4 with a 3.0 V6. This past Saturday, we had a typical afternoon thunderstorm in central Florida. As I drove through this rain/storm, I noticed my ABS light flickering, and my speedometer guage bouncing; then it all went back to "normal". After about 30 seconds, it did the same thing, then back to normal (ABS light went out, and speedometer worked normally).

In doing some searching here and googling, I found that my year Ranger has an ABS/VCC sensor located on the rear axle. This sensor sends the "signal" to the PCM, who in turn controls the speedometer.

Could the heavy rain have gotten onto this sensor causing it to make the ABS light and speedometer react the way they did? I drove the truck Sunday in nice, hot sunny weather, and I had no symptoms as I did on Saturday.

 

Yes, good call, VSS(vehicle speed sensor) connector is most likely issue, check it for water intrusion or corrosion.

I can't remember the years but Ford moved the PCM(computer) connector high on the firewall near the center, and in that location water could come in from the rear hood gasket.
They added a cover plate for the connector when this issue arose, but of course only if there was a problem under warranty, lol.
So if VSS connection looks good I would check where the PCM connector is and if it looks like water has made its way to that connection, if so disconnect battery!!, then remove connector and check it closely for corrosion.

 

My 2000 Ranger has the PCM at the top center of the firewall and I wondered sometime back if this was a potential problem!.....

During this rain storm, the wipers were sloshing a lot of rain water towards the bottom edge of the outside grill area, between the rearward hood seam and this grille. These symtoms are now making sense!

I'm going to make my own bracket to cover this connector to the PCM this weekend; that and use some good insullation tape around the connector where it attaches to the PCM.