Hi,

I have a 98 Ram 1500 4X4 with a 360. i noticed back in april or may that my speedo was acting up and i had a abs and a brake light on. i left it for about a month and then i replaced the speed sensor in my differential. that didnt work and i kept getting the same code. so i replaced the sensor in my trans by my transfer case and replaced the one in my diff again and the check engine light is on and i still have a abs and brake light on. it is shifting goofy at highway speeds and sometimes the speedo works but it only works when it rains. so if somebody could help me out and point me into the right direction that would be appricated. Thanks.

 

Sounds like you might have a short some where or bad ground wire. Download the service manual from the FAQ/DIY section and start tracing wires. And when you replaced those sensors, did you remove the negative battery cable before doing so, to let the PCM reset and clear the codes?

 

i didnt disconnect my negative battery cable. and i did them in july.

 

Well you should have. Might want to try resetting PCM now for the hell of it. And btw , what brand sensors have you been buying?

 

ok, how do i reset the pcm? and the napa brand which i think is Beldin

 

I also had this problem and discovered tgat the wiring harness that is under your steering column in your truck may come loose. I had mine put back in and it works fine. hope this helps. I have a 1999 dodge ram 1500

 

Disconnect the negative battery cable and turn the headlights on for 30 seconds or so. Turn the lights off and reconnect the the battery cable.



This is also a some thing to look at. If you have a tilt wheel and use it all the time, the wires running down the column can get damaged.

 

Thanks guys, i was testing wires and my speedo works, kinda, it bobs at speed and doesnt show me the correct speed. my check engine light is off, and my abs and brake lights are off when i start the truck and then after about a 1/8 mile the lights come back on and the speedo bobs. will resetting the pcm fix that?

 

I'm thinking you have a defective sensor on the diff if the wires and plug seem ok. Maybe you can swap for another one under warranty? And this time disconnect the neg cable first. And you can try resetting the pcm now, but I dont think it will help.

 

ok. i reset the pcm, and it worked for a 1/4 mile and then the lights came back on and the speedo started to bob. so you think it is a bad sensor? ok, ill try and replace the sensor and i will disconnect the neg battery cable. thanks again for your help.