Linking headlights to interior light

[geraintthomas]

Anyway - It's a good project that you're doing with the photometric sensor and all, and I'd be keen to see it work, but for now and for the purpose of the original question and the reason for the thread - is there any way to just simply wire up the parking lights to the courtesy lights?

Even with the use of a 5 pin relay, for example? That's literally all I'd want at the moment - I didn't expect this to get carried away into photometric sensors that leave lights on for 10 seconds after the car is turned off etc etc. Like I said, I massively appreciate it and it sounds amazing (and be sure to show us when you're done), but I'm just interested in turning the parking lights on when the courtesy lights come on.

So is there a way to do this with a simple bit of wiring and relays? This is me talking off the top of my head and probably absolute rubbish, but could the courtesy light's ground wire be wired into a relay, that when given a current, tells the relay to send power to one of its pins, which is the 12v feed for the sidelights? That may not make sense, but it's something like that which I'm thinking of.

Is that not possible?