Originally Posted by 99Ranger3.0
It is just the speedometer and the odometer. I will check the 40 pin plug tomorrow. Besides that is there anything else you can think of?
For 99, the raw VSS signal goes from the ABS sensor to either the GEM or the 4WABS Module, depending on whether you have RABS or 4WABS. From there, a conditioned square wave signal goes to the speedo, PCM, speed control, etc. That only leaves a few possibilities:
Bad ABS sensor (common);
Bad speedometer (possible);
Bad GEM/4WABS Module (not likely);
Opens or grounds in the wiring or connectors.
I suggested looking at the 40-pin because it is a known trouble spot and easy to check.