GM's system is frustrating for a lot of people because instead of using a simple and reliable ten-dollar relay hooked to the ignition system to turn on the low beams and the tail lights, they chose to use a computer module to run the high-beams at eighty percent of full brightness. That means you shine your high beams into other driver's rear-view mirrors. They have to dim their mirrors during daylight hours, so they do not see everything going on back there. The engineers found a solution where there was no problem.
You should find your daytime head lights turn off when the parking brake is applied. A manual switch could be added to do that, but I would not drive like that because the red "brake" light on the dash will be on. That light is also used to warn of low brake fluid level and a failure in either half of the brake's hydraulic system. You do not want the warning light to be on all the time because you will never know when another problem develops.
A better possibility, if the parking brake does not work, or if you want the head lights to be off while driving, is to research the wiring diagram and look for a wire to the module that can be cut and have twelve volts switched onto it. That would trick the module into thinking the parking brake is on.
Monday, January 9th, 2017 AT 2:38 PM