I've discovered that When sitting at idle, my Speedo will bounce up and down from 0-to almost the 20 mph mark, then second I start rolling it works fine. Also now the ABS and brake warning lights will sometimes come on and then stay on until I shut the truck off or go off while driving. The Truck is an 03 Quad cab 2WD with a 4.7 and only has the standard rear wheel antilocks, not 4 wheel. I am assuming it has to be a ground issue. It has no effect on the drivability of the truck except for the fact it's annoying! Any help or insight would be appreciated.

 

I think this exact problem was discussed a month or so ago and it was fixed with a speed sensor. They kept hearing almost a humming noise in the back of the truck sometimes.

 

I would remove both battery connections, clean them and reboot to see if that helped first.

 

That is one of the first things I plan on doing but with the snow and cold we've had lately, I haven't been to "motivated" to mess with it.

 

Any idea on what to search to find that thread?

 

https://dodgeforum.com/forum/3rd-gen...eedometer.html

https://dodgeforum.com/forum/3rd-gen...-light-on.html

https://dodgeforum.com/forum/3rd-gen...r-problem.html

here's just a few......use the search button at the top and type speed sensor.

 

Check the speed sensor first before you check anything else. Should be your problem.

 

speed sensor. Just happened on my rear end swap. they are fragile and like to break. It will most likely come out in peices and the bottom half will need removal with a flat screwdriver, needlenose pliers and paitence.. look in with a flashlight and make sure you can see the gears or you dont have all of the peices out. the top of the hole where it goes into will need to be cleaned of rust and debris or the o ring on the new one will not seat. Do not force it or you will break the new one. All it is is an electro magnet and the lead wires are very fine inside. if you push down on the end of the plug, the wires have a tendancy to snap off. Open up your old one when you get it out if it came out whole and you will see what I mean.