[Supras] Strange electrical problem

[JAMES]

I got a electrical problem with my 89T. Some times when I am driving the "battery" , "taillight failure" and "brake"
 warning lights come on.  Before they come solid , they flicker and the heater fan motor surges high and low.
 And if it is at night I can see the headlights surging  brighter. 
   I have check to see if it is charging after the lights come on and it is. All of  the taillight and brakelight 
 bulbs are good. It is not low on brake fluid. The altenator is about a year and a half old.
  Could it be the voltage regulator going bad? Any suggestions would be appreciated.
 
                                                           Thanks,
                                                                         James