Headlamp Warning Buzzer - D22 STR

G'Day Members
Thought I'd tackle a seemingly simple task today but failed, so, I'm seeking some advice from all you "sparkies" out there.
I want to install a warning buzzer that tells me I have left my headlights on when the ignition is turned off. (Following a series of mishaps thought it would be a better option). I bought a simple buzzer and was going to connect the earth of the buzzer to the earth side of the drivers door interieor light switch, and a live to the headlight switch...easy!! Didn't pass GO nor did I collect $200 as there is not a dedicated earth on the door switch, they all share a common chassis earth.
So, has anybody esle carried out this mod and if so how did you do it?, I'm guessing a relay may be the answer. Information gratefully received.

It should be as easy as using a normally closed relay (not normally open) with:

Input power from the headlight circuit
Relay switch power from the ignition circuit
Earth to vehicle body/negative
Output to sound device of your choice (perhaps not your horn)

This way, when the ignition is turned ON, the relay changes to "open" (since it is normally closed, activating it is like turning off a switch).

When you turn off your ignition, if the headlights are off, there's no power to go to the buzzer so it stays quiet.

If you leave your headlights on, as soon as the ignition is turned off, the headlight power feeds through the relay and sounds the alarm.

Done like this, it will consume no power at all while your headlights and ignition are turned off.

I'm sure there are kits for it though, with diagrams. Jaycar?

Hey Old.Tony
Thanks for the reply.
I wonder if you could help me a little more, let me explain, I'm not an electrician by trade but can follow clear instruction and have just successfully installed dual battery, split charge for fridge, brake controller, Waeco RAP's, and feel quite confident in doing the job, but could you be a bit more specific in what wire goes where,
e.g. Pin 30 = ? Pin 85 = ? Pin 86 = ? Pin 87 = ?
Many thanks
MAP

I'm not auto electrician either, but I owned a Volkswagen Kombi ... ought to say enough! Let me google up the kinda info you need.

Most of the relays you see in the auto shops are Normally Open relays and the terminals are numbered like you said above. You need a Normally Closed relay or a single pole double throw relay which I think are numbered differently.

This is what you want:

Wire a simple headlight alarm | Redarc Electronics

The relay they have used is the single pole double throw I mentioned, you can see the Normally Closed contact is numbered 87A.

Okay, got the answer. Use a Single Pole Double Throw relay. Should have pins labelled 85, 86, 30, 87 and 87A on it.

Pin 85 goes to ground.

86 goes to your ignition hot line - whichever you're using to determine when your ignition is on.

30 should go to your headlight power line.

87A should go to your siren.

87 should not be connected.

Relays 101

*bows down to the mighty Google*

Thanks Jason, that confirms that I'm not barking up the wrong tree too. And all those years stuffing around with the dub paid off somehow, at least!

All good, my first car was a beetle as well, 1962 model. Damn 6 volts!

Thanks to you both Old.Tony & Jason, I appreciate your help and advice. Will gather the necessary parts and have another go!!
MAP

That's an amazing coincidence! Mine was a '62 beetle, we cut out the guards in the engine bay to squeeze a 1500cc motor in it.

Moved up to a 1970 kombi and really did some miles in it, got pics of us on our honeymoon in it, and not-so-fond memories of having to re-wire the engine bay just north of Willow Tree at near midnight because the engine had caught fire and stuffed all the wiring.

Took me 45 minutes - ahh, the days of simple are gone now!

I put a buzzer into the center dash behind radio, linked into the radio dim power and always on power. from jaycar i just grabbed a relay and a piaso buzzer. cost next to nothing and took about 15 mins to install. works great, lights on+key on= quiet, lights on + key off=noise!

edit: found the info i used to do it

http://www.gbnetwork.co.uk/circuits/carlights/car_light_reminder.html

Hey Wozenme
Thanks for the additional information. Between the three of you, I've definately got it covered now. All is good and no more "lights left on" problems.
Cheers
MAP

Nice work mate. Nothing beats doing it yourself, exhaust excluded.

Hi Jason
Thanks for the compliment.
Mechanic by trade although that was many years ago, but electrics.......NEVER my forte but I can following instructions. As you say, "can't beat DIY" especially after seeing the absolute "pig's ear" of a job the local Nissan dealer done on my spotties, bare wires and unsupported relays, also found a nearly chaffed through loom too whilst fitting the Auxiliary battery controller, an absolute disgrace to the trade!!
They'll NEVER get my business again.
Ciao for now.
MAP