FWIW, I had a sort-of-similar situation. The first problem was the front sensors. The second contributor was alternator brushes on their last legs. The final turned out to be corrosion in the connection of the power lead to the ABS computer.

It was a lot of time and money to get a light to go off!

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe