1997 Ford F250 4x4 HD

My vehicle has about 197,000 miles on it and for the most part still functions properly. I do have an odd “happening” sometimes and here is a description:

I will be driving along and all of a sudden the digital odometer readout will go blank and the speedometer will drop to 0 if I was going 60 mph or below or to 120 if I was going over 60 mph.

Where do I start troubleshooting?

Bob

I’ve got the same vehicle… 7.3 diesel, unless I’m mistaken in some of the gasoline models getting the “HD” badge.

I don’t know about the EO4D automatics, but the manual ZF-5 transmission does not have an electrical pulse-generator pickup. The vehicle’s odometer and speedometer, as well as very rudimentary ABS system relies upon the pickup on the top of the rear differential.

One of the things you could do would be to jack up the rear of the vehicle, block the front wheels, and let the vehicle sit with the rear wheels turning. A decent scanner should be able to scope the output of the rear ABS/speedo sensor. Another thing is to check the obvious and look at the wiring to make sure it hasn’t been snagged and/or grounding out anywhere.

Thanks for the reply. I’ve got a 5spd manual transmission so I will check you rear axle sensor test suggestion.

Bob

Let me know what you find.

A problem with the sender should not make the odometer “go blank” …That sounds like a problem with the digital display driver…

Since the odometer and speedometer problems seem to be related I would check for a loose common connection to power, or ground possibly, to those areas.