TomGeorge:
Hi,
You need to check that your door switch switches gnd or batt pos.
Most cars have gnd switching, this makes for a very simple mechanical door switch.Tom...
Ok. So I just checked the wiring diagram I have for my vehicle and yes, it looks like the dome light switch switches ground. But, what I would really like to do is splice into the dome light that way whenever any door is opened all the lights come on and it "triggers" the Arduino/alarm. Because, I think if I use just the one switch, it'll only "trigger" the Arduino/alarm when that one door is opened. I could be wrong but I'd rather just do what I stated and splice into a light. So, is there any way to detect said voltage coming from the the wire splice and have the Arduino "trigger" the alarm and make the siren go off?