WI_72_Headlight-Cut_Add-on.jpg

This modification turns the head lamps turning off when ignition is off.  This prevents one from leaving lights on during daylight and not noticing that they are still on after getting out of car - thus  draining battery.

This is a quick and dirty patch that is easily installed at/near the fuse box, thus not messing with the dash harness and easily installed/removed without any undo-able hack to the harness.  A simple 12VDC Bosch type relay intercepts the headlamp power-up wire (RY).  Coil is activated by the ignition wire (G or BW).  Add ground to chassis.  Use appropriate connectors to nearly just 'plug-in'.  Could be mounted to strut tower next to other stock relays.  Being in the engine bay, you'll want to ensure water-tight assembly.

Note-1: Most Bosch auto relays draw about only 150 mA so should not effect ignition.  Lower power relays (35 mA ?) are also available.

Note-2: You could also easily add a simple 12VDC RC circuit (resistor and capacitor) here to effect a 3 to 20 second slow shut-off delay.  Apply in parallel to the relay coil feed wire.  Capacitor +ve to feed.  Resistor between Cap -ve and ground.  Suggest 3500uF Cap with 5-20K resistor (variable).  Experiment.