I have already changed the VSS in the rear diff,twice,traced the wires to look for fray or splices(searchin old threads),and it won't read mph off the AE. Fuses were also checked.
What other things would cause this?
Washed the truck and it worked for 1.7 miles,since then and before then nothing.

 

Check the connector at the ABS module. If in doubt, clean with electrical parts cleaner. Also verify for certain that your VSS connector is properly seated and making a circuit. Some aftermarket sensors are hard to get the clip installed correctly.

With your symptoms, the ABS is not seeing the sensor. Sounds like the issue might be with the wiring between the ABS and the VSS.

 

Ok, I will go through n check it again. Thanks

 

Where's the abs sencor?

 

Where's the abs sencor?

Sorry for souble post.

 

Went through n rechecked all connections and wiring. Even bought a second vss. Can't get it to work. Guess of to the mechanic. I hate electrical problems.
The vss sensor is on the rear diff,the abs sensor is on the front of the brake master cylinder assembly.

 

I had a ground problem when my 7.3 had your symptoms, it was the one right in front of the drivers side battery.

 

Tom,I think your right. That's where I mounted my fuse box and relay for the airdog when i installed it. Crossing my fingers,will check it after work.

 

That's possible.

If you have the factory towing option with 7 pin RV connector under the bumper, or any add on connector for trailer towing, see if moisture got inside the back or front of it. Moisture or water in connectors can cause cross circuiting resulting in no speedo, abs, and no or inter-mitten cruise control and more.

Cross circuiting from moisture in certain circuits would cause a flashing od light. If you pressure washed under the hood or under the truck, you might want to pull connectors in the areas washed, check for moisture and dry them with compressed air. A wet connector is likely since it happened right after a wash.

Racer
Product research and development consultant to the automotive industry.
Certified specialist on automotive electronic control systems, diesel and gasoline engines, Custom transmission, Powertrain, Engine and Torque Converter Builder.

 

I hooked up a Truspeed speedo correction unit, and the power wire to the unit came unplugged. I had all the symptoms you had. The speedo unit connects to the ABS unit. I could drive for a little while and the then the truck would just shut off. Hooked the wire back up and the problem when a way.

 

VSS is on top front of the rear diff. VSS is for the rear ABS as will as speedo.

 

It actually started working for 1.7 miles after I power washed it. So it could be in my tow wiring too. Yay

 

I had the same issues with my 2001; no cruise, blinking OD. Ended up being a bad PCM. The transmission would also go into limp mode if I used reverse but if I went straight to drive it would "sort of work" but felt different. Got a used PCM for $200 and all problems went away-been running fine for a year now. It doesn't sound like this is your issue but thought I would add my $.02 in case someone else, in the future, is trying to diagnose this problem.

 

Not my issue,but thanks.
My trans works fine.

 

You were right Tom!!! Thank you for the help. Reps sent ASAP.
The ground in front of the drivers battery where I bolted the fuse box for the airdog. Everything works again. Spectacular. Thanks everyone for your input.