My speedometer/odometer has never worked on my truck since Ive owned It. Ive changed the sensor in the rearend & I checked the wiring. Ive also done the gauge check by holding in the trip button while starting. Everything seems fine but still no speedo...any ideas??
thanks,
Doug

 

Did you take voltage drop tests along the wiring for the rear sensor?

I replaced mine when I was having no speedo issues, didn't fix the problem. I then started tracing the wiring from the PCM, to the sensor itself. After taking readings and then my voltage dropping near the fuel tank. I cut back the loom to find corrosion in one of the 2 wires. Cut that out, connected back together and has been fine for a couple years. Probably still is, I just don't drive the truck anymore.

 

I used a 'AA' battery with 1.7volts, i hooked It up at the rear diff wiring & had full 1.7volts at the wiring connection by the front fender. I will check from the front connection up to the PCM this weekend.

How many volts should I have?

 

A dealer with DRB might be the easy way out. I believe the signal goes through two computers and three wiring circuits. Signal can be lost anywhere or even the cluster.