How to add a headlight warning buzzer

[talljordan]

Not once have I ever forgotten my keys in the vehicle and locked them in, however I frequently leave my park lights or headlights on, and return to a flat battery.

I decided to add a second buzzer to my 72 super that warns me if I open the door and the lights are still on. Here is how to do it!

First, we need +12V from the park lights. To get this you can tap into fuse 1 or 2, both of which operate the park lights. Hook this up to one side of the buzzer (which I installed next to the dimmer relay).

Next we need switched ground from the doors. The easiest place to access this is the passenger side. Splice in a second wire to the connection here that will eventually run to the other side of the buzzer.

HOWEVER, there is an important note. The door switch is not actually a true "switched ground", it actually is sometimes +12V, namely when the interior light is on switched mode, and the doors are closed (see wiring diagram). This terminal receives voltage through the interior light. This means that if you close door and the park lights are off, the buzzer will run in reverse and never shut off, draining your battery. The buzzer receives power through the dome light, then sinks it through the headlight switch acting as a ground.

To solve this, we simply need to prevent current from running in reverse. This can be done with a diode, I simply soldered a diode in line with the "ground" wire that I ran from the passenger side door to the new buzzer. This way current can only flow from the buzzer to the door, and never from the door to the buzzer.

Job done! Now my car buzzes at me if I forget my lights on while the doors are open.

_________________
1972 Super Beetle, Parked until adequate restoration funding is acquired in restoration!

Wanted: Male computer diagnostic plug end

[vamram]

Nice. I miss the working dying mouse-like buzzer that worked on my '72 Super for the key and seat belts.

What did you use for the buzzer? The original VW buzzer relay mounted in the fuse panel? Any pictures the installed buzzer?
_________________
"Men are qualified for civil liberty in exact proportion to their disposition
to put moral chains upon their own appetites. -Edmund Burke

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...we hardly knew ye. Sold 2025 for peanuts.
Click to view image
Save the Supers!!

[busdaddy]

Most piezo buzzers are already a diode and only work with the polarity one way, I usually connect at the fuse box between the park light circuit and the ignition circuit, if the lights are still on when the key is turned off the ignition circuit becomes a ground for the buzzer.

Jordan's method does allow sitting with the parking lights on if that's something you do often.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[talljordan]

Im using a stock piezo buzzer, my original one worked, and then I bought another working one from a scrapper for a couple bucks. So I have 2 stock buzzers in the fuse box.

Neither of these buzzers have an internal diode. Both worked regardless of polarity, thus my added diode. If your buzzer has an internal diode, the install becomes much simpler.

The one thing that my implementation doesnt allow, is if the lights are on and a passenger leaves the door open, it will buzz. If it ends up annoying me Ill add a NC relay to the switched power that interrupts power to this buzzer when the car is running.
_________________
1972 Super Beetle, Parked until adequate restoration funding is acquired in restoration!

Wanted: Male computer diagnostic plug end

[Cusser]

I installed Radio Shack buzzers in my 1971 and 1970 VWs. There used to be a product called LiteMinder available before manufacturers started adding these.

https://www.amazon.com/HAHIYO-Electronic-Continuou...sc=1[/url]
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[busdaddy]

Those are very similar to the ones I use, piezo, not analog like the OG VW key buzzers.
There were some really cool ones available in the 80's that were dedicated to the job, I recall having a couple that would quit beeping after 30 seconds so you could park with the parking lights on but the engine off. I even had one that had a built in wiper delay feature as well, a 2 for 1 crappy little box you stuck on your dash and wired in using the crazy Japanese translated instructions.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[talljordan]

Took a photo yesterday! I also installed a fuel pump cutoff relay, so my fuse box is now full.

_________________
1972 Super Beetle, Parked until adequate restoration funding is acquired in restoration!

Wanted: Male computer diagnostic plug end

[bsairhead]

[talljordan]

Wiring is still a WIP. I havent hooked up the wipers or fan yet. So its from that.
_________________
1972 Super Beetle, Parked until adequate restoration funding is acquired in restoration!

Wanted: Male computer diagnostic plug end

[bsairhead]

[bsairhead]

Sorry about the double post. I made a cocktail came back and forgot I already hit send.