I've got a 98 ram 2500 cummins w/manual trans. Abs and brake lights are on. Checked fuses, brake lines for leaks, drums aren't wet so I assume wheel cylinders r good, replaced speed sensor on diff. Didn't help lights r still on! Any advice

 

Welcome to DF

It could be a sensor or a module. Do you know if you have RWAL or 4 wheel ABS? I will move your post to the 2nd gen ram section.

 

How do your brakes feel? The line that runs to the rear likes to rust out right above the gas tank. Leak isn't always evident.

That said, you have two, or four wheel ABS?

 

It is rwal and the brakes feel good. No lose of fluid but I will take a closer look above the fuel tank for a brake fluid leak!

 

If you don't find anything there, pull the drums, and have a close look. There isn't always evidence on the outside for a failed wheel cylinder.

 

Problem solved, come to find out the previous owner put bigger wheels and tires on the truck. But didn't program in the increase in revolutions per mile. Had a friend hook up his scanner and do the update, problem solved. No more abs/brake lights. Now I can try to get this tps sensor( check engine light) problem fixed!