F-350 Speedometer not working?
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Junior User
Joined: Oct 2004
Posts: 72
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From: The Republic of Texas
F-350 Speedometer not working?
New to forum and have a major problem with my '99 F-350. The speedometer stopped working along with the ABS light came on and the overdrive button's off light started blinking. Any ideas of where to start to fix the problem? I've already checked the fuses under the dash, deprogramed the Hypertech power programming and sort of looked at the fuses under the hood!!!!
Thanks in advance,
tex1313
Thanks in advance,
tex1313
Tuned
Joined: Jun 2004
Posts: 275
Likes: 9
From: San Antonio
Look at your rear diff... I believe there is a pickup sensor there and that's where your speedo gets its info (not the tranny)... replace that first...
one of my friends has a 350 psd that he uses on his farm and if you backed up a long ways the speedo would quit working for a day or two. he took it to the stealer and they ended up replacing that sensor, I guess the diff gears would stir up metal flakes in the bottom if the diff and carry it up to stick to the sensor, which is not much more than a magnetic pickup that counts the gear teeth as the rear end turns and feeds it to your computer. and if my thinking is right, if the comuter does not know for sure how fast your going (other than rpm and pressure) then it doesn't know when to shift into OD, therefore blinky, blinky...
I do not know if the rear abs uses that same sensor, if the wheels are turning, the gear is turning... if it sees no gear turning, it may see a rear brake lockup, therefore an abs malfunction.. Hope it helps
one of my friends has a 350 psd that he uses on his farm and if you backed up a long ways the speedo would quit working for a day or two. he took it to the stealer and they ended up replacing that sensor, I guess the diff gears would stir up metal flakes in the bottom if the diff and carry it up to stick to the sensor, which is not much more than a magnetic pickup that counts the gear teeth as the rear end turns and feeds it to your computer. and if my thinking is right, if the comuter does not know for sure how fast your going (other than rpm and pressure) then it doesn't know when to shift into OD, therefore blinky, blinky...
I do not know if the rear abs uses that same sensor, if the wheels are turning, the gear is turning... if it sees no gear turning, it may see a rear brake lockup, therefore an abs malfunction.. Hope it helps
Senior User
Joined: Sep 2004
Posts: 130
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replace the vss ( vehicle speed sensor ) in the top of the rear axle housing. this will fix your problem. the sensor is now available aftermarket if you don't want to go to ford, 20-25 dollars. the sensor puts out an a/c siganal (sine wave) and it can be ohmd for a test proceedure, if you want to do it. clean around the sensor before pulling it out ( one retaining bolt) the slide the old out and the new in. have a ford day!
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PapaTruck
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1999, 2003, 2004, 350, dash, f350, ford, inop, malfunction, powerstroke, problem, speedometer, stopped, work, working
