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Old May 5, 2015 | 11:05 PM
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fordman2000's Avatar
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Default Speedometer not working

I have a 94' F150 and the speedometer and odometer stopped working. All the other gauges work though. Also there's something wrong with the transmission. When you press the gas it revs high and shifts hard. It also takes awhile for it to shift. If anyone has any ideas of what this may be please tell me. Thanks.
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Old May 6, 2015 | 02:43 AM
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yep, the vss or whatever it would be called on that car
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Old May 6, 2015 | 09:17 PM
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The VSS (vehicle speed sensor) on top of the rear diff sends a signal to the PSOM (speedo module) and that tells the the transmission when and how to shift.
First thing to check is the VSS - take it out and clean it,or replace it (Motorcraft only) check the wiring from it especially from it to the frame.
The next thing in line usually is the PSOM itself, which can be removed from another cluster and swapped in to yours. You should be able to use one from any 92 to 96 cluster, but 94 up are the best ones, they're less sensitive to weak VSS signals.
The PSOM is the whole center module in the cluster.
It stands for Programmable Speedometer / Odometer Module
Watch the mileage on a replacement - that's where your mileage is stored.
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Old May 6, 2015 | 09:28 PM
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Ok thanks hopefully this fixes it.
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Old May 9, 2015 | 04:01 PM
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I fixed the speedometer. Fuse #8 was blown out. It wasn't the sensor after all.
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Old May 13, 2015 | 08:34 AM
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So apparently you didn't have interior lights either, glad you found the problem- had this happen to me, took the fuse out so I wouldn't run the battery down having the doors open and forgot to put it back it, freaked out thinking I broke something doing dash work until I realized I had forgotten the fuse.
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Old Feb 20, 2016 | 06:50 PM
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Originally Posted by fltdriver
So apparently you didn't have interior lights either, glad you found the problem- had this happen to me, took the fuse out so I wouldn't run the battery down having the doors open and forgot to put it back it, freaked out thinking I broke something doing dash work until I realized I had forgotten the fuse.
I have exactly the same problem. Fuse 8 was blown. I replaced it but the speedo and interior light still don't work. The new fuse has not blown. But I got nothing
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Old Feb 20, 2016 | 07:40 PM
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Have to pull up a wiring diagram (try BBS industries or just google). Could be whatever blew that fuse is now a fried wire. A bunch of things on that circuit (that shouldn't be IMHO). But check your owner's manual for everything on that fuse, if they're all not getting power, it would probably be in or close to the fusebox. If some things are and some aren't, that might help narrow down the break in the circuit.
Sometimes it's as simple as the connector at the back of the fusebox - sometimes it's a real guessing game.
One thing about power issues - they're a pain to chase down but they're usually cheap to fix; if you're not paying someone 100.00 an hour to do your looking for you.
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