Dakota abs light

Brother Dustin has a new to him 1999 Dakota r/t. We've been slowly getting it back in shape from neglect and abandonment before he bought it.

This week it started setting off the abs and brake light after 10-12 miles. 

We've done front rotors, pads,lines and calipers. Rear shoes, hardware, wheel cylinders, hose. Turned drums. 

It stops, and stops well. About as good as i ever remember mine stopping, honestly. Better than my gmt400.....

Anyway,  im at a loss on diagnosing it. I started down Google and decided that the hive has the answer quicker, easier and cheaper than anything I'll find on Google. My cheap obd2 code scanner won't pull any abs codes. Is there a paperclip trick, or a key dance or something? And way to diagnose it without special equipment?

Pull the bulb because 90s dodge abs is dangerous. 

You can key dance it for codes. It's hit or miss on abs codes. 

I don't know how to pull them without a decent scanner beyond that. 

If the speedo works, it's not the rear speed sensor. Most of the r/ts seem to have 4wabs which has a module on the pump. I know in other models of that time that was a pita to most and problems.

Following for the answer. My 99 Durango is acting weird in braking too.

there is a single wheel speed sensor on top of the diff on the rear axle that is notoriously funky.  They get abused by the elements and fail, or sometimes just get tired and then start working again all by themselves if you ignore.  Cheap part, easy fix if you like laying under rusty Dodges.