Had to put a new VDO oil pressure sending unit in my boat last night. I connected the light blue wire to the gauge post on the sending unit. Everything works. Went to connect the tan wire with the light blue tracer line, which should be for the engine alarm, and when I touched it to the post it sparked. Turns out I have 12v going through this wire at all times, key on and off, even batteries switched to off. Is this normal? I actually don't have an engine alarm installed right now, the previous owner took it out for some reason. I was just hooking up that tan wire so it wasnt dangling in the engine bay. A full alarm system is on the "to-do" list. Right now, just need to know if the engine alarm wire is supposed to have 12V? I am having trouble tracing where that wire goes to. Pretty sure its not, as that tan wire should go to a ground and when the switches closes it sends ground to the buzzer and completes the circuit?