I have a 1987 Toyota pickup 4cyl 22r carburated, I just replaced the alternator on it because the charge light on the dash had come on and it was causeing my motor to rev really high, I removed the positive cabel on the battery and changed it out, when I placed the battery cable back on, my oil and brake light in the dash had come on, when I turned the key and started my truck the lights go off, when I go to turn the truck off the oil and brake light come back on, so I had to remove the fuse 40amp under the hood so that the lights would go off without draining my battery, I have never had this problem with my truck!
The older model Toyotas were made ein Japan. For some reason if a fuse is blown it will light the lights on the dash. Sometimes if you have low brake fluid it will do the same.
There is no rhyme or reason the the lights lighting, it just happens. Check ALL you fuses both inside and out. Check all fluid levels. Also check the ground cable. Remove it from the engine, firewall and clean them.
Sometimes a blown bulb in the brake lights will do the same thing.