Speedometer/odometer failure in '92 Bronco

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Feb 25, 2002 | 10:44 AM

bigric

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Fleet Mechanic

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From: Round Rock, TX

Speedometer/odometer failure in '92 Bronco

I've got a strange problem in a '92 Bronco 351W: the speedometer and odometer are completely dead. Additionally, the transmission now shifts at radically different points, but since all these systems are tied together, I'm really not surprised by this. I haven't noticed any other electrical problems since this problem started.

I've checked the fuses both under the dash and in the power distribution box. I'm sure there is a simple fix here; my searches have come up with numerous references to the power control module. I'm looking for any feedback on this problem (I'm sure somebody has a 10-word solution), and have two additional questions: have I likely lost the odometer count, and has the odometer been counting since this failure?

Thanks in advance for everybody's help.

Feb 25, 2002 | 01:51 PM

MustangGT221

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From: Topsfield, MA

Speedometer/odometer failure in '92 Bronco

Odometer has not been counting, about 95% sure it hasn't. Check the ABS speed sensor on the top of your differential. You'll find two wires leading to it so it should be easy to identify. Check it for corrosion and follow the wires back to make sure they havn't been cut by anything. Could be a failure in the sensor, and they are pretty cheap to replace so i'd get one if you don't find a cut in the wire. Start with that and we'll go from there.

Feb 25, 2002 | 02:38 PM

67Stangboy

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Speedometer/odometer failure in '92 Bronco

Before you go and buy a new sensor for the speedo, you should check the gear that the sensor goes on. I don't know where the sensor is ont the auto, but mine was in the end of the transfer case. Make sure that the teeth on the gear don't show any wear. If they do I would start with that. Good luck

Kit
1990 Ford F250HD, 351w, zf 5sp, 4x4,
RS900 Shocks, Rear air bags

Feb 25, 2002 | 02:47 PM

bigric

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From: Round Rock, TX

Speedometer/odometer failure in '92 Bronco

Thanks for the advice. I haven't checked the speedo gear yet, but felt it unnecessary since the odometer doesn't even give a reading. Failing other avenues, I'll have to give it a shot. As far as the ABS sensor goes, does anybody know what sorts of voltages it's supposed to give if I'm checking it with a meter?

Feb 25, 2002 | 10:58 PM

bigric

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From: Round Rock, TX

Speedometer/odometer failure in '92 Bronco

Thanks for the advice. I haven't been able to see the truck yet (somebody is out driving it), but I did have a thought-even if the speed sensor or ABS sensor was out, wouldn't the odometer at least still show some value? As it is, it displays nothing. Is there another sensor or computer connection that may be causing this as well?

As soon as I can get under the truck I'll replace the ABS sensor anyway I guess.

Feb 26, 2002 | 01:23 AM

ncvote

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Speedometer/odometer failure in '92 Bronco

I had the same problem in my '92 F150. All of a sudden one day the odometer/speedometer quit working and the shifting was not right. The speed sensor is located in the top of the rear differential. My first idea was to replace it, the part was less than $20 from a Ford dealer. That did not fix it. I then took my truck to a reliable private repair shop where they said the instrument cluster was bad. The instrument cluster contains the circuitry for the PSOM (Programmable Speedometer Odometer Module) which I guess was some how bad in my case. I got a new cluster from a truck at a junkyard. Only disadvantage to this is that you get whatever mileage the new cluster has on it. There is no way of adjusting it. The new cluster may have also had its calibration changed for bigger tires or gears. Do a search in the archives if you want to find out more about how the PSOM operates and how to change its calibration. That is how I fixed my problem, yours may be similar. Hope this helps!

Nick

Feb 26, 2002 | 10:16 PM

bigric

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From: Round Rock, TX

Speedometer/odometer failure in '92 Bronco

Thanks everybody for the help. Replacing the sensor on the top of the differential didn't fix the problem, so I'm picking up a cluster from a yard tomorrow. Pretty reasonable price too, so what the heck. It's not like it works now any way. Again, thanks to all.