I have a '99 Dodge Ram 1500 with the V6 in it and recently some new problems have popped up. First my ABS and Brake warning lights on the instrument panel have come on and decided to stay on. Second, my speedometer does not work until I reach 20mph at which time it jumps rapidly to read 20mph and then works fine for any increase in speed there after. When braking the needle reads correctly until it reaches 20mph and then it drops all the way to 0mph in the same rapid motion as seen when accelerating. Any ideas?

 

I'm having the same problem! except mine does it at about 40-45 mph. a diagnostic test at auto zone says that the speed sensor (located somewhere on the trasmission) is bad. anyone know where it's mounted?

 

Speed sensor is located on the tailshaft of the tranny on the driver side. Eay swap, be quick it can be messy. Around $30

 

I have a 98 dodge ram 1500(5 speed) with the same problem and ive looked over the tranny 5 times and still i cant find the speed sensor, i went to the parts house and they gave me the right part and everything, i was woundering if its in a diff. location then the automatics.

 

On the ABS, I am not sure how closely related this is, but on my Nissan Pathfinder my ABS light was coming on. While I was getting new tires mounted the mechanic said that my wheel bearings were shot and needed replaced and that was probably making my ABS light go on as well. Sure enough, I threw in some new front wheel bearings and it fixed the problem. I don't know how though since it only had rear ABS.

 

the speed sensor on my 2000 5.9 ram is located on the rear axle housing, not on the transmission. it gets messed up by metal shavings in the axle that interfere with it's magnetic sensing. if this is the case with yours, you'll want to change the axle oil and clean it out as well as you can, or it will recur.

 

this will fix it. I had the same problem back in January... 1 new sensor and about 10 minutes.

 

This is a common problem. Mine just went out. The speed sensor is on the top of the rear dif. Get the part from the dealer (about $40-50). Jack up the truck and rest the fram on jack stands. The axle will drop down this should give you plenty of room. The easiest access is from the passanger side from the door tward the axle. Just un-bolt the old sensor and place the new one. Use a zip-tie to re-anchor the wires.