Brake light on the instrument cluster is always on in my jeep. Sometimes it shuts off at startup but will come back on with an audible ding within 5 seconds. Fluid is at correct level in the reservoir and hand brake lever is down. Awhile back too it to oreillys and their scanner picked it up saying low voltage in the system. They cleared it but the light is still on and they haven't picked it up again. Any ideas?