Originally Posted by superthrooper
So as I was driving home the other day the speedometer started jumping. dropping 10 mph then jumping 5. After a few minutes my entire speedometer quit working. I read multiple forums all pointing towards the rear abs sensor. I purchased a replacement at napa for $20 part #530000. after replacing the sensor in the rain (that was great..) my speedometer still doesn't work.
I then went back to Napa believing it was a crappy sensor and got another sensor. hooked it up and still nothing. No Check engine light or ABS light. The only thing I can relate this issue to is the installation of a overhead console and the connection to speed sensor.
If VSS(vehicle speed sensor) was bad, or it's wires, then CEL(check engine light) would come on, and in a 2000 Ranger the ABS light would come on as well since they both(Computer and ABS system) use the same sensor on the rear axle.
The 2000 Ranger would have a GEM(generic electronic module) behind the radio.
The GEM controls lights, wipers, and quite a few other things.....including speedometer.
The VSS signal runs from axle to ABS and Computer, then from computer to GEM, then from GEM to speedometer.
GEM is programmed for axle ratio and tire size to set correct speed to show on speedometer, I think only dealers can program the GEMs
If the newly installed "overhead" has any electrics then they would have to have messed with the GEM wiring.
So it could just be a loose connector