Need a relay for headlight warning chime

Thread Starter


Joined Nov 6, 2015
So I've been searching unsuccessfully for a relay, I'm starting to think that it may not exist. My truck does not have a headlight warning chime that will alert me if I leave my headlights on while my ignition is off. My idea is to use a relay to switch the 12v chime on/off. I want to run power from my headlight fuse to the relay, and also power from my radio fuse (which loses power when the ignition is off) to the relay, so that when BOTH are energized, the chime circuit is open, but if the headlight switch is powered while the radio (accessory) is not powered, it chime circuit is closed. That way, if I turn my ignition off while my headlights are still on, the chime will sound. Does such a relay exist? Or perhaps there's an easier/better way to hook it up. Any thoughts and input would be much appreciated.
You can do what I did in a 1982 vehicle.

In that vehicle there was a diode to the door switch on the driver's door.
I wanted, a switch to ground on the driver's door only, so I added a diode there.

From there I went to a buzzer and the +side of the buzzer to the parking light circuit.

So, if the driver's door is opened and the headlights are on, the buzzer sounded. It's not the same as ignition off. Just don't sit in the vehicle for 5 hours without opening the door which I did once.

I had that car for 17 years and I had to replace the buzzer probably 3 or 4 times. The heat got to it.

The cars I drive now are nuts:
One leaves the radio on until you open the door. The only thing that shuts off the headlights is the parking brake. Turn off car, apply parking brake and restart. Just opening the door leaves the lights on for 3 minutes or so.

The other car won't turn off the lights until I open the door.

These things don't help much when a deer stops in front of you. Turning off the lights briefly is an ordeal.
e.g. turn off car, open door, close door. wait, re-start.

I know, I had a deer stop in front of me on a back road usually at dusk. Your vulnerable to be hit in the rear.

Then again, you can always move the sign: