There are a few noises that we - as car owners - truly dread. The sound of buckling panels and breaking glass. Your car alarm going off while you're in the shower. That clunking noise from the bottom-end of a hi-po motor. And how about that clicking you get when your battery gives up? That last one is enough to drive you mad. Often, that's because there's something you could've done to prevent it - like switching the headlights off after you'd left the car... Grrr.
If you drive the kind of car that the manufacturer couldn't spare another couple of lousy bucks to put a headlight-on buzzer in - you're in luck. You can do-it-yourself at home in around 15 minutes! The same goes for those cars with only a headlight-on warning light - these things are extremely easy to overlook. Especially when the bozo who designed the light coloured it orange - exactly the same shade as the dusk sunlight streaming in over the dash... One car that fits this description is my Holden VL Commodore - our hook-up guinea pig.
To remedy this potentially infuriating situation, all you need is a spare $4 for a buzzer and some hook-up wire. Major Australian electronics retailer - Jaycar - sell both of these 12V piezo buzzers for only $3.35 - and they both fit the bill perfectly. Their catalogue numbers are AB-3462 (larger one) and AB-3459 (piddlie one). Being polarity-conscious (meaning, they've got a positive and negative side), it's easy to wire either of these buzzers to sound whenever the headlights are on and the circuit is earthed through the car door switch (which, obviously, happens when you're getting out of the car). For those situations where you want to leave the parkers or headlights on, simply close the door and the buzzer will put a sock in itself. Perfect.
This is the buzzer that we elected to use - it looks nice an' durable and sounds just like an OEM lights-on buzzer. It is, at 90dB, quite a bit louder than an original fitment item though. Being polarity-conscious, the red wire represents the positive side of the buzzer, and the black wire goes to earth.
The first job is to find an adequate positive power feed for the buzzer. Any dashboard light that illuminates accompanying the headlights will do just fine - the easier it is to access, the better. Here, we've removed the VL's windscreen wiper/washer control, which contains a bulb for nighttime illumination of the switches. If you can't identify which colour wire running into the connector is for the bulb, simply probe them to see which one gets 12V when you switch on the headlights. Gotcha.
Strip back a short length of the insulation on the designated positive feed wire and connect (by soldering if possible) the red lead of the buzzer. Depending on where you plan on locating the buzzer, you may need to piece in a length of hook-up wire to give you the reach that you need.
Now we go in search of a switched earthing point that's linked to the driver's door switch (passenger door switches are sometimes only linked to a door ajar warning or individual in-door lights). If you can't locate the single wire that runs from the back of the driver's door switch, you may need to unscrew it and tap into the wire immediately behind the mounting flange. You will certainly need to use a length of hook up wire to tie this wire to the buzzer. Pretty obviously, we connect our hook-up wire to the remaining black lead on the buzzer.
At this stage it's best to ensure everything is working as it should. Switch on the car's headlights and open the door. Does the buzzer sound? Hell, yeah - but it's very loud isn't it? Now either close the door or switch off the headlights to shut the buzzer off - before you deafen yourself. Oh, and don't worry about the demands that this little buzzer will place on the rest of your dashboard illumination wiring - it only draws up to 15mA.
Depending on how loud you want the buzzer to be inside the cabin, you can now chose to wrap the buzzer in electrical tape and/or mount the buzzer somewhere where the high pitch screeee will get slightly muffled. In our case, we didn't bother to tape it up - it is a
warning buzzer after all. To our ears, its SPL was adequately suppressed by gluing the buzzer just up inside the Commodore's instrument cowl.
Now just make sure you've neatly tucked all the wires away so they won't flap around or get in the way and - hey, presto - we're done!
No more stressful returns to a flat-as-a-tack battery for us!
Contact:
Jaycar Electronics
www.jaycar.com.au
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