87 5000tq

[tombin]

I am looking at buying a 1987 5000 TQ.  it has 100,000 miles on it for
1200 $.  I have test driven the car.  It runs like a dream.  Not squeaks,
or weird noises comming from anywhere in the car.  No oil leaks under the
motor, runs real quiet.  Everything looked good to me.  THe only question
I have is, when I take of the e-brake the is a ding from the display in
back of the steering wheel that says brake with a ding behind it, like an
idiot light.  THis shows up where the OK sign is when you turn the car on?
Can someone tell me what the is referring to, and should I be concerned
about it?