The brake fluid level indicator sensor is a normally open circuit, closed when the fluid level is sufficient. You should be able to shunt the connector to get the lamp to go out. If you do this and the lamp stays on, then you have another sensor or switch in the system that's not happy, or missing, or the brake fluid level harness is not wired correctly into the system. The EBCM (Electronic Brake Control Module) receives the input from the brake fluid level switch, and controls the IP lamp. If you pacify all the switches/sensors, and still have the lamp on, I'd suspect an issue with the EBCM, or a weak/missing ground in the circuit. If you haven't installed the late model EBCM, that could very well be the problem, with the BCM missing the input, or the input is not correct from the park brake switch (which is monitored by the BCM)