One problem related to brake light on has been reported for the 1998 Chevrolet 1500. The most recently reported issues are listed below.
When trying to leave a parking garage, I depressed the pedal and the brake light came on and the pedal almost went to the floor. Got it home without incident. Took a look under the truck and the entire brake line was rusted. The place where the brake line broke was in a place where you could not physicall reach it. The other lines running across the axle were also horriably rusted. Now I have to take all of them off, measure, bend, and refit. I refuse to pay gm to fix their shoddy work. I owned a 1991 GMC sonama with over 300,000 miles on it and never had this problem.