Within the last three days four different things have happened with my truck. The truck is a 2000 F-250 Crew cab, short box 4x4 with a 7.3 PSD.

1. The ABS light on the dash came on. I was towing a new four-place snowmobile trailer with electric brakes the first time it happened. When I was fueling up, I shut the truck off, and the light stayed off until yesterday(no trailer hooked up). Now it comes on occasionally. I am guessing a sensor???

2. The electric brake actuator display blinks occasionally when I have my foot on the brake and the turn signal on(no trailer hooked up). This does not happen all of the time, and it has never happened before this week.

3. The overdrive off light on the shifter was blinking for a few minutes. The overdrive was still functioning while the light was blinking.

4. While the light was blinking on the shifter, the speedo was not working, and no miles were clicking on the odometer. I stopped at a stop sign, and the speedo started working again, and the overdrive light continued to blink for about 30 secons after and shut off. This has not happened since the original incident.

You guys have been a big help in the past, and I am looking for a little more help. Any input would be appreciated. Thanks.

 

I'd start by checking all of the wiring going to the rear differential. Wouldn't hurt to pull the speed sensor out of the rear diff and clean it.

 

Probably the rear speed sensor breaking down when hot. Both the speedo/OD and the ABS systems use this signal. Should read about 1300 ohms.

 

Fordtech1--You da man! I checked the forums and found my problem --ABS light on, speedo not working below 35 mph and intermittent flashing of Overdrive Off light. I checked the sensor as you suggested and found it open circuited. For less than $30 I'm back to normal, at least my truck is. Thank You Fordtech1 PS The new sensor measured 1863 ohms.

 

...and NoMo