switched power

How do I wire a relay to remote power my headlights on an old BMW which requires the ignition to be switched on or started in order for the headlights to operated.

tap into the headlights where the harness connects to the bulb on the wire that shows 12v+ when the low beams are on. you might have to do this on both sides. connect 12v+ to 30 on the relay, and the headlight wire mentioned above to 87. connect a ground(or pos, which ever is oposite of your trigger) and your remote trigger to 85 and 86. Or you can use the remote trigger and 2 relays, one to provide the trigger for the headlights and the other relay to provide power to the acc wire that is required for the headlights to opperate. it's up to you.

jc18750, Thanks for repsonding to my post, that was the idea I had in mind, but ultimately, what I would lke to do is have Illuminated entry when I arm/disarmed. Each arm and disarm cylce would last 30-60secs. I'm be afraid when I disarm, I get in to the car, start it up and turn on the headlights I would fry the wiring because of oversupplying current to the headlights. Would a diode work to isolate the current? My other idea involves using relays and removing the stock wiring from the headlights, but first I'll have to check to see if the stock setup uses a switched negative.

a diode would work to isolate the current, but you'd need two for each light. you could also pull it off using relays 2, each side..

the above diagram would work if the neg is NOT switched. this diagram below is for your dome light on for 30 seconds when you arm/diarm your alarm.