Where is the Speed Sensor on a 1999 Ford F250 7.3 L diesel 4x4?

Question edited for clarity and make some real sentences.
Question moved to model category.

See the first video, but by the sounds of it, you need an auto electrician with a pro grade scan tool computer to diagnose these faults electronically. ABS, Speedometer and Transmission Solenoids.

https://www.google.com/search?q=1999+Ford+F-250+4x4.+The+ABS+light+is+on%2C+and+the+speedometer+doesn%27t+work

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The rear one is in the top of the differential. The front ones will be at the wheels.

Pull the codes.

there is an ABS sensor on top of the rear axle, and they are known to cause these symptoms-check the wiring, connector, and replace it if necessary, they are about $30 and is held in place with one bolt.

The abs sensor is the one located on the rear differential, not the speed sensor. It is located on the rear of the transmission housing.

If you lose the speedometer, replace the rear differential speed sensor on top. If the speedo is ok, then it's your ABS pump/solenoid unit in the engine compartment left rear side. Most of the 99's have only the rear ABS, not front so don't look at the front brakes for the issue.

From what I have read this sounds like a problem with the second speed sensor located on back at the rear axel on top of the differential. If the cable is loose or the sensor is bad it will cause the brake light to come on and the speedometer to act funny. There are two speed sensors...one in the transmission and the one on the differential. The second one is probably the problem.

sound like the control module is acting up. hal switch is in the rear diff. you really need a scantool to monitor what is going on with the sensors. or your going to pull your hair out. i work in a shop. it can be few different things. u really need to know if everything is working as it should. best of luck.

YOU WILL NEED TO HAVE ABS DIAGNOSED. IT IS MORE THAN LIKELY AN ELECTRICAL FAULT OR COMM PROBLEM. POSSIBLY ECU OR A SPEED SENSOR. MOST COMMON TRY TO REPLACE DIFFERENTIAL MOUNTED SENSOR ON REAR DIFFERENTIAL, MOUNTED RIGHT ON TOP OF DIFFERENTIAL,CAN'T MISS IT HAS WIRE GOINF TO TOP OF DIFF AND HAS 10MM BOLT HOLDING IT IN.

same problem here, found 3 places that say it is the abs sensor:

Had this problem with my 1999 Ram 1500. There is a sensor at the top of the rear differential for the ABS system. That sensor went bad and replacing it took care of the problem. What caused mine to go bad was apperantly water got into the differential when launching and loading my boat. check to see if gear lube needs to be replaced also.
The answer above is perfectly correct. When the ABS sensor on the diff goes bad the speedo no longer will work, the odometer stops recording mileage and both brake and ABS light comes on. You also loose O/D or "Lock-up" in the torque converter. The sensor is inexpensive and can be changed in about 30 mins. Good Luck!

The fix for your truck is the ABS speed sensor located in the top of the differential housing , held in with one stud . Your speedometer is calculated through the ABS controller. Replacing that sensor will fix your problem.