I have a 91 d350 diesel dually crew cab that has the g360 5 speed transmission. The speedometer does not work. I have checked the nylon gear that drives the distance sensor and it is good. The wires fron the distance sensor to the cluster have continuity, and the B+ to ground pin has battery voltage. The manual that I have says to use the drive train manual to test the distance sensor, I do not have that manual. Does any one know how to test the distance sensor, and or the speedometer head it self? i would appreciate any help on this. Thanks for any advice .

 

I want to let everyone know I found the problem with the speedometer it self. I found a discolored resistor and a section of the printed circuit missing on the circuit board in the speedo. i replaced the speedo with a unit out of a salvage yard and the truck now has a working speedometer.