First off this is a Nissan Frontier.. not a g35 but yall seem to know what ur talking about maybe can help..

When i turn my truck off my headlights start flashing on and off (the high-beams specifically). i have to pop the hood, pull the fuse and put it back in for it to stop.. and then it still sometimes starts back up... my horn just went out for some reason also.. could it be something wrong with stock alarm sensor? also if anyone knows of a nissan frontier or nissan forum plz help!!

Thanks,
ben

 

Sounds alarm related. Take the fuse for the stock alarm out, or disconnect it, and see if you still get the problems. Nothing else should make you headlights flash. Alarm is the only thing I could think of that would.