Hello tmolnar- The anti lock light indicates a problem with the ABS system, and has nothing to do with the condition of the drums/rotors.. If the red brake light was on that would indicate a problem with the hydraulic system/leak.
The brakes will work fine with the abs light on, just the anti lock part of the brakes wont work.
When the abs light is on, there is a code stored. To retrieve the code you need to ground test terminal 3 and count the flashes of the abs light. The test connector is under the dash, to the left of steering column.