1993 Roadmaster Code 63

This 63 Code (Valve Relay Circuit) is making me goofy! I've traced wires-pulled a relay & sometimes the code (abs light) stays out 4 a week - sometimes the next day it will appear.It has a Bosch 2U system.NOW I've tried 2 clear the code & it won't go out.The brakes work fine.It has a 350 chevy motor.$50.00 is a bit much 2 b trying relays.The relays plug in under the hood on the control unit.PLEASE Help ! I bought it new & the wife wants 2 keep it.Then all i need is a pumpkin 4 my K20 1971.
Diagnosing ABS problems can be a very long and drawn out procedure, especially if it’s and intermittent problem. As in the light staying out for a few days and then popping back on. With you saying that you now cannot clear the code, whatever is going on has finally failed. Which I guess is kind of a good thing because now someone that knows the system has the test procedures and equipment should be able to find the cause.
Why I someone is that if the test procedures are not followed to the tee or if you misinterpret what is being asked; it will take you down the wrong road and probably cost you more then having someone at least diagnose the problem for you.
I just had a look at the test procedure and there are 17 specific tests that branch out in different directions depending on the results of these individual tests.
For me to try and tell you how to do these tests over the Internet would be very difficult, beyond my ability anyway.
Dan.