06 w900 speedometer jumping all over

No they are different depending on tranny for nut and they make about 5 diff size strap kits call dealer with vin they should have them

 

no I haven't. thought about throttle position sensor. but hate to throw parts at it.

 

Throttle position sensor has nothing to do with the speedometer, check over all of your wiring.

 

when mine acts up the truck actually reacts the same as the speedo....ie with cruise on if the speedo slows down(goes from 60-50)so does the truck, and same if the speedo speeds up. that's why I was thinking tps. What would the symptoms of a bad tps be?

 

Bad tps would be no throttle input and or codes in the ECM. So does the speedometer go down and then the truck slows down or is it at the same time? I thought from the previous post it sounded like the speedo slowed down the truck sped up to catch up?

 

speedo goes down then truck follows same when speedo goes up truck speeds up as if it is trying to catch where the speedo is at. when cruise is off speedo still goes up and down but no reaction from truck.

 

Sounds like you have a wiring problem from the speed sensor to the engine ecm. While it is on cruise control the engine is trying to compensate for the loss or increase in speed that it thinks is happening. Get a good wiring diagram that shows the pins in the ecm and the harness that runs back to the speed sensor and test all of the wiring.

 

Check the resistance from the ecm pins to the pins at the connector for the speed sensor. Make sure they are not open, shorted, have high resistance or shorted to ground.