I bought a this from an auction and just spent months sorting out air suspension issues, Today I got the car from the shop and was driving it around and one time I started it the red dash Brake light was one. I know on some cars the emergency brake pedal will trigger the light if it is bumped down a few clicks so I pressed and released the pedal twice yet light stayed on. Then when I put it in reverse gear the sound of the car automatically releasing the parking brake pedal kept sounding until I put the car in Drive.

Any ideas where to start with this?

 

Check your brake fluid level first. If it's not low, then get the ABS codes pulled with a capable scanner