I have an auto 92 sc300, I never use the parking brake however I moved my car to prep for a big storm and thought it would be a decent idea to use it just in case, afterwards even when I put the brake all the way down the light stays on, as well as when im driving I hear a squeaking coming from my rear rotors, I dissembled the parking brake handle and sensor, and even when I manually push the sensor all the way down it still stays on, as well as losening the brake like I’m still hearing a squeaking

 

Check your brake fluid level and rear brakes for a possible seized caliper.

 

yes, the light goes on when e-brake engaged; it also goes on when brake fluid in reservoir is low. Top off fluid if low, keep eye on rate of change and investigate cause if continues.