Locate dodge ram 1500 speed sensor?

The speed sensor on my 1994 Dodge Ram 2500 was on top of the differential housing on the back axle, the big bell housing between the rear wheels. It's held in a rubber housing which takes a bit of work to remove. If you're asking about this because the speedo/cruise control has stopped working, it might be the speed unit or it might be the there's a break in the wire. If you replace the unit and speedo/cruise control still doesn't work, it's probably a break in the wire and you can wire it directly from battery to unit to cruise control for the fraction of the price of a garage repair.

Pre 1998 the speed sensor signal comes from the back of the trans/transfer case. 1998 and later the speed sensor signal comes from the rear axle speed sensor.