I have an '89 Reatta, had been sitting for about 8 years before I acquired it, about 10 months ago. After general clean up, tires, a/c compressor and relay replacement, my daughter's been driving it back and forth to school since last November. Last week, she told that there as an intermittent light on the dash, which turned out to be the yellow ABS light. It only comes on for a couple seconds when you apply the brakes. Touch the brake pedal and it lights up, a couple seconds later the red brake light flashes once and the yellow light goes out with the red one. The brakes appear to work OK, and the fluid level is where it should be. The only ALDL code that I get is '21' which as I understand it, could mean just about anything. Step 7 of the 'Brake Test' provides a good 'thump' as well. Wondering if anyone has the best plan of attack for this problem. Like I said, the brakes appear to be working fine, but would like to correct this before it becomes something major. Thanks.