Car is a 89 Olds 88 Royale. My brake light comes on when ever the outside temp gets above 30 degrees. Brakes work fine, about everything is new, rotors, pads, drums, shoes and wheel cylinders. Only thing not replaced are the front calipers and master cylinder. Could the sensor in the master cylinder be bad? Would a high brake fluid level cause a problem? Any other ideas?

Thanks,
Eric

id check for a short somewhere the warmer the wires get the easier they conduct electricity