Re: Faulty ABS? Light turns ON during commute...
B.C. - The manual I have makes a point of saying that the 87 - 92's have RABS1, and they don't have a keep-alive memory to hang on to codes, and it can't be troubleshot using the procedures of the RABS2, which my book does cover. Seems they must have had problems with people trying to troubleshoot the old one with the new procedure.
But just wild guessing on yours, it would seem it could be either a bad connection, or the pickup on top of the rear diff having trouble. Your problem would seem to be something happening when the system is just idling, as it happens when you're off the brake. It's probably a cheaper problem to fix, as it wouldn't seem to be in the hydraulic unit ('cuz yer off the brake, and have been for a while). But I wouldn't replace ANYTHING without having the proper procedure, running the tests, and troubleshooting it down first.
Sorry I can't help, you need a manual for one of the years 87 through 92. UncleDon