I have a 2001 Blazer LT 4x4 (with 4 wheel abs). Recently the ABS light and the red brake light have been coming on. They come on only some of the time and it can happen at any time from start up, to driving while braking, and even driving while not braking. In addition sometimes there is a sound that sounds like a solenoid opening and closing repeatedly coming from somewhere under the hood (only while driving). If I had to guess I would say thesoundis coming from electronic brake control module. I have had the code scanned but I don't recall the number. The verdict was that it was NOT a wheel sensor and the EBCM would most likely have to be replaced but I am hoping not to have to spend $700+. Anyone that has had any experience, comments, or advise chime in.

 

It would be a lot easier to diagnose if you could remember the code (there are about 35 possible codes)
From what you say, it sounds like there is an internal short in one of the 6 solenoids inside the EBCM.
If it is an internal problem and you have some tools and skills, you could by one from an auto wrecker, install and bleed it yourself and probably cut your cost in half.