Pontiac Repair: 2007 pontiac grand prix low beams will not turn off

Question
I have a 2007 Pontiac grand prix. My low beams come on automatically when it gets dark. They will not turn off now. We have replaced the multifunction switch and still not working. We pulled the hdm module and they went off, put it back in and they work. We have recently installed an aftermarket cd player, I do not know if that has anything to do with it, but also my door locks do not lock when u put the car in drive, and I do not think that they lock at all, because I locked my car the other night and the next morning it was unlocked. Also my trunk button on the driver door does not work. Can hear a clicking under the steering column when u press it. Not sure if any of this ties together but it all started after we installed the radio. Please help!!!

Answer
Hi gina:

as for the head lamps that headlamp control relay/module is why the light would not turn off it stuck on and it will happen again. usually it's the other way around that the lamps will not turn on.  as for the door locks if they work with the switches and the key fob the options in the BCM for some reason are not working look in the owners manual for customization for door locks and change the mode. for the trunk lock if you hear the clicking but it will not pop the trunk it could just be a relase actuator in the trunk it's self. with anoy of these issues it's just a guess with out seeing it. good luck :-)