Ford Repair: ABS light on intermittently - 1994 Lincoln TC, brake fluid reservoir, dash light

Question
Recently the antilock dash light has started coming on after running a few miles--not every time I use the car but sometimes.  It does not go out until I turn off the key.  No abnormal symptoms or behaviors with the brakes.  The brakes seem to work normally although I have not had to use the ABS feature.  The brake fluid reservoir is full.  The brake pads are at about half--not worn down.  Brake pedal is normal.  The wiring to the sensors appears to be undamaged.  Car is equipped with traction control.  Is there a special ABS code reader different from the engine code reader?  Would shops other than a dealer typically have an ABS code-reading tool?  Am I looking at big bucks?  What typically causes the problem?

Answer
Hello Douglas,
    First , I have to apologize for taking so long to get back. I was having some computer trouble at home.
    There are many different causes and faults that can cause the light to come on. To retreive diagnostic codes, you must use what is called the "STAR" tester, which is a factory developed tool that the dealers used up until fairly recently. They are available to the public, but finding a private shop that owns one will likely be difficult. You may have to take it to the dealer to at least get a ballpark range of whats wrong and what it might cost.
    The only things that really cost alot in the system are the hydraulic pump and motor unit(which don't fail often), and the control module. I don't know for sure how much you are looking at without researching parts prices. Dealerships will typically charge 1-2 hours labor to diagnose, and maybe even repair it. Good luck!  Shaun.