i have a 99 2500. when i drive the truck and go over 40 mph the abs and brake light comes on and the speedo jumps from 0 to the speed im going. also the brake lights dont come on when i press on the brakes. need your HELP!!!!

 

Sounds like your ABS switch. Its on top of the rear pumpkin and it sticks down inside the rear end housing with some wires going to it. You can get one from dodge dor about $30.

 

will that also be the cause of no brake lights?

 

I dont know if my truck had lights when my ABS switch went bad or not because I changed it the next day. Did you check your fuses or under the truck for any naked wires?

 

ya i checked the fuses will have to check wiring thanks

 

could be two different problems, check all the bulbs or test with a multimeter/test light for power at the lights, It could be a bad brakelite switch as well. also check the wiring from the speed sensor to the main harness near the frame, it can be broken internally and if you pull/run your thumb against the wire you should find it, or it could be a bad sensor, check the easy stuff first before throwing parts at it

 

not to steal a thread but I have an o1 dodge that the ABS pump stays on all the time. I pulled the fuse just so I could drive it but I would like to get the abs fixed. what do you think is makeing the pump run? I thought there might be a problem with the front sensors in the hubs but have not had time to take them apart and find out.
DM01

 

pretty sure you will not find a problem in the huibs causing the ABS pump to run, as when there is a wiring or sensor issue the abs defaults to standard brakes, I'd bet on a controller issue or something wrong with the abs/pump assy