headlight on warning buzzer

[casinojoe1]

hello all, (new here). i've got an old corsa 1997, i'm looking to build a circuit that buzzes when i open my door when the lights are on, anyone got any ideas on how to make a circuit that will do this?

 

[Joe G]

"you have left your lights on indercat" turned up when i searched for "headlight reminder alarm" told how to do it.

 

[KeepItSimpleStupid]

I did exactly that on one of my vehicles. In my case, there was +12 available when the lights were on and ground available through the door switch when the door was open.

There were diodes in the car.

So, all it took was a buzzer between the (switched +12) a diode connected to the door switch. The isolaiton was already present, so it only worked with the driver's door. The diode is effectively a (wired OR) gate.

If the isolation isn't present, then you have to add another diode to the door switch.

The buzzer I used had to be replaced periodically because it didn't hold up over the temperature extremes and 17 years.