no cruise,abs, and the speedo keeps rhythm to my left signal light

[bushpig7]

Take a truck out of California (even though it was built in Ontario originally) and introduce it to cold, salt and rough roads and it will show you all its flaws directly.
Not only does the speedo keep rhythm to the signal but it also dances at any speed over 35mph. When I turn the headlights on it instantly drops to zero and then goes back its abnormal dance. When I brake it sometimes jumps also. It was working fine and I'm not sure what started all this. I thought it was the sensor on the rear diff but changing it got no results. decelerating does seem to change the way it malfunctions but only for an instant. I looked in the stuff here about bouncing speedo needles but nothing dealt with the speedo being affected by other switches and circuits. I checked ground #200 and #201 since they seemed to be the ones that all the circuits mentioned above used but I couldn't see a problem with them. Oh yeah.... the high beam indicator light on the dash stopped working a month or so ago and the only time it works is now and then when the lights stay on with the switch off and the truck off. Could this also be related to the speedo problem?

 

[85f250dually]

did you say before that it had to have drls added to pass inspection? could they have messed up the wiring installing them? sorry im not to good at wiring so i cant help much

 

[DragRag]

Check the rear end speed sensor, plug, and/or wiring leading to it. Go from there...

 

[bushpig7]

I'm pretty sure it isn't the plug itself as I just cleaned it up and it looks good. but I haven't followed the wires all the way up to the cab yet. guess I'll try that, maybe two wires are rubbed through somewhere. to answer the question about the DRL s. Its just a little 4"x 4" module you plug in @ the front of the truck after you remove the factory installed jumper plug. Remember, this truck was made in Canada originally.

 

[tbone0418]

Check your rear antilock module its on the frame of the truck close to the front of the drivers door. The speedo cruise and abs go through that module. Also check the connection at the cruise control module under the hood on drivers side fender well.

 

[towcat]

bushpig-
long time no see.
how else is the truck doing? get it passed inspection?