On a 98 Dodge Ram 2500 Diesel (12 valve), why do the ABS & Park Brake Lights come on together. After the initial start up, they go out. They then come back on together and stay on. This initially happend after being on gravel roads. Once washed, they stayed off. When the monsoons hit, the lights came back on again & have stayed.

How come? Is it to do with the speed controller? Is it moisture? How can this be fixed? Is the CAB creating the problem? Is it clearable with DRB111 scanning tool?

I know someone will have the answer. Thanks, in adavance.

 

Welcome to the site! Does you cruise control still work? I'm not sure what you washed before but if the lights are coming on again I would look at the plug to the rear wheel speed sensor, located on the top of the rear diff. You can take the plug off and clean it and put it back together with dielectric grease. You may have to replace the sensor, (a dealer only item) and that usually clears up the problem. For info on the replacement do a search on this site, it's very easy (10 minutes if you take your time). Another cause can be the stoplight switch. Although it can be tested, they are about $12.00 at Auto Zone.

 

Cruise still works, but fluctuates sometimes. I'll try the speed sensor.

Thanks

 

You don't have your signature filled out and I forgot to ask if you have an auto, there is a speed sensor on the transmission.

 

Checked OBD scanner & found no codes. Will check the transmission sensor. Probably it.

 

I believe it is the sensor on your rear axle, if it is associated with getting it wet, unplug it and clean the connector halves with contact cleaned and try some dialectric greese, or other kind of stuff to keep moisture out. What ever the case it is associated with that rear sensor, I had the same thing on my 95 a while back.

 

You won't. The scan tool for the ABS system is only available to DC dealerships.

 

I want to thank everyone who helped.

The solution came through a friend, Bob, who said there may be corrosion in the wiring even though the connectors looks good. I found corrosion in the connecting wiring (dumb idea) between the wiring harness and the speed sensor. He was right. I put 12 volt power to the connecting wiring & had no power. Then made my own temporary connector to see if it was the problem. It was.

Dodge is the only place to buy this connecting wiring, however, they only supply the wiring with the speed sensor. I'm now the proud owner of a new speed sensor.

Dielectric grease & lots of electrical tape - this won't happen again.