I have a 96 blazer AWD 4.3. The red brake light has been on since I’ve owned it for about a year now. I have replaced a few brake lines front pads and rotors and adjusted the rear. The brake pedal is firm and the brakes work wonderfully. Fluid level is perfect and the parking brake switch is confirmed good with my meter. The priority valve has a single wire hooked to a switch. I unhooked and removed the switch, everything seems normal there. The ABS hasn’t worked either but the ABS light never comes on. Lastly my scanner is unable to connect to get the brake related codes. Engine codes aren’t a problem. Any thoughts on where I can look to get this light off?