Tempermental Snowball

[Joe Dirt]

I know I don't like to get moving in the morning, but neither does Snowball. (It will also do this in the evening when I come home)

Always done this since I've had her, but figured if anyone has dealt with this before...

When I leave for work, truck cold, about 6-7 minutes into my commute on the highway, the speedo starts jumping +/- 5mph of the actual speed. If the cruise is on, it reacts to the speedo and either cruises or jerks forward to keep up- but it will do it even if the cruise is off. After about 20 seconds of this, it's over, and everything is great.

It is always about the same amount of time into the trip, and for the same duration.

I replaced my VSS a couple months ago and it still does it, and I've had 3 different clusters in it so far, so that's not it either...

Anyone have thoughts?

 

[BrooklynBay]

Did you ever open the steering column to check the wiring? I remember reading a similar issue in Gears Magazine. It was on a Ford motorhome/Econoline van. The wiring in the steering column was being pinched, and intermittently shorted by the tilt column mechanism. Do you notice the transmission shifting erratically when this happens?

 

[Joe Dirt]

It's usually only when cruising on the highway because of my driving habits and schedule, so I don't know the shifting issue, because the truck is already cruising in overdrive. Maybe I'll take a different route tomorrow to see if I can check that out.

I'll have to pull the steering column covers and check out the wires as well. Did the article say anything about the timing of the situation? Seems odd that it's always the same time after starting, and lasts the same amount of time. It never does it after the 30 second incident is over, nor if the truck doesn't completely cool down for an extended period of time.

 

[BrooklynBay]

Try tilting the column the next time this happens. In that article, it said that the lady who was driving would suddenly experience erratic shifting, and the speedometer would start to jump. They also replaced the speed sensor, and it didn't help. They opened the column to chech the cruise control wiring, and found pinched wires which were being stretched when the column was at a certain position.

 

[Joe Dirt]

I'll do that. Is the wiring integrated closely enough that it will cause the speedo to jump even if the cruise is off? Not just disengaged, but completely off?

 

[BrooklynBay]

All you would need is an intermittent short to a ground in the column regardless if it's on or off.

 

[Joe Dirt]

True. I'll check it out- might have something to do with the expanding of materials as things warm up? Weird gremlin! Thanks BB, I'll get on that today...

 

[BrooklynBay]

Ford did some interesting things when they put wiring in places with moving tracks. For example, there was a recall on some model Fords for wiring catching fire under the front seats. The power tracks had the wiring harness snaked through the track instead of under it. The wires would get rubbed against the metal track everytime the seat moved until the rubber got spliced, and shorted. The recommended fix from Ford was to unplug the wires, and place them in the correct location under the track instead of going through it.