Mechanics

SPEED SENSOR

1994 Ford F-150 • V8 4WD Automatic • 125,000 miles

1994 F-150 5.0L 4x4. Speedometer and odometer went out and transmission is******** when it changes gears (auto). I changed VSS but same problem. I also changed fuse under dash with no luck. Any suggestions? Could it be one of the large fuses under the hood in the connector box?
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Salgar444
January 13, 2011.




Check the fuses to make sure, but your first guess is mine too. If the check engine light came on, have the computer scanned to determine if there is a code relating to the trans. If there isn't a light, check to see if there is power to the speedo / odometer. If there is no power, start tracing wires back to the pcm to see if anything is disconnected, corroded, or damaged. You may actually want to start at the VSS to see if there is power there and trace that back. It will save time. There is one other thing you need to check. Under the dash (behind the fuse block) is a module known as the GEM. On many of these model year vehicles, the windshield would leak (not enough for you to see) and get the GEM wet and eventually cause it to short. Check the module for any evidence of water getting to it. One last thing, if you haven't, you may want to try a different VSS. With all the importing of products from other countries, there is a chance you got a bad one. It happens more than one thinks.



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