I have a 2003 Ram 1500 4x4 and the ABS and brake lights come on and stay on. No problems with the speedometer. It works fine. Also, the cruise control was working until the lights came on. Now, the cruise will not turn on. The cruise light will come on when the truck is not moving, but the light will go off as soon as the truck is in motion and will not set at any speed. Are these all related?? Any ideas on a fix would be greatly appreciated! Thanks.

 

yes change the brake light switch located at the top of the brake peddle.

 

I changed the brake switch but it didn't fix the problem.

 

I'd check out your ABS sensors. They are either clogged up with metallic debris or are corroded.
Those 2 issue's cause what you are speaking of.

 

I have the same thing, my rear ABS and VSS sensor isn't hooked up properly. It's the plug on top of the rear diff

 

I think you're onto it there. Check the speed sensor on top of the rear diff. It will also make the brake/abs light to come on. From what I've read sometimes it'll make the speedo do weird things, sometimes it won't.

 

This just happened to me today while sitting @ the bank drivethru. ABS Light and the Brake Light is on. My speedometer is going up and down also.

* Anyone have a picture of the actual part that needs to be replaced on the rear differential?

* Is this a dealer only part or can I purchase this at AZ, NAPA, etc.?

I noticed on another post that you have to be real careful not to mess up the part when replacing the sensor. Any suggestions...I'm willing to tackle anything that could save a few dollars and not make me have to roll up at the dealer.



Thanks,

DK

 

I'm sure you can get the sensor at an auto parts store. I think the dealer sells 'em for pretty cheap(30-50) depending on the dealer if I'm not mistaken. It's an easy change out, it's on top of the rear diff.

speedsensor.jpg?t=1269289963

 

plug a scan tool into it! I had the same problem and it was my front wheel bearing the sensor went bad. if its that fix it quick cause your bearing will fall apart!

 

My 03 does the same thing (ABS Brake light) when ever I play around the diff, especially when it's realy cold -20 to -40. i,ve fixed it twice, once by wiggling the plug and the second time when that didn't work I tapped the housing with a small ball been, two or three wacks and the light went out. Has been good for 3 months now. Next time will replace the speed sensor which I believe is not expensive. I have never had issues with the speedometer.